/external/apache-harmony/luni/src/test/api/common/org/apache/harmony/luni/tests/java/lang/String2Test.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.harmony.luni.tests.java.lang;

import java.io.UnsupportedEncodingException;
import java.util.Locale;
import java.nio.charset.Charset;

public class String2Test extends junit.framework.TestCase {

    String hw1 = "HelloWorld";

    String hw2 = "HelloWorld";

    String hwlc = "helloworld";

    String hwuc = "HELLOWORLD";

    String hello1 = "Hello";

    String world1 = "World";

    String comp11 = "Test String";

    Object obj = new Object();

    char[] buf = { 'W', 'o', 'r', 'l', 'd' };

    char[] rbuf = new char[5];

    /**
     * @tests java.lang.String#String()
     */
    public void test_Constructor() {
        // Test for method java.lang.String()
        assertTrue("Created incorrect string", new String().equals(""));
    }

    /**
     * @tests java.lang.String#String(byte[])
     */
    public void test_Constructor$B() {
        // Test for method java.lang.String(byte [])
        assertTrue("Failed to create string", new String(hw1.getBytes())
                .equals(hw1));
    }

    /**
     * @tests java.lang.String#String(byte[], int)
     */
    @SuppressWarnings("deprecation")
    public void test_Constructor$BI() {
        // Test for method java.lang.String(byte [], int)
        String s = new String(new byte[] { 65, 66, 67, 68, 69 }, 0);
        assertTrue("Incorrect string returned: " + s, s.equals("ABCDE"));
        s = new String(new byte[] { 65, 66, 67, 68, 69 }, 1);
        assertTrue("Did not use nonzero hibyte", !s.equals("ABCDE"));
    }

    /**
     * @tests java.lang.String#String(byte[], int, int)
     */
    public void test_Constructor$BII() {
        // Test for method java.lang.String(byte [], int, int)
        assertTrue("Failed to create string", new String(hw1.getBytes(), 0, hw1
                .getBytes().length).equals(hw1));

        boolean exception = false;
        try {
            new String(new byte[0], 0, Integer.MAX_VALUE);
        } catch (IndexOutOfBoundsException e) {
            exception = true;
        }
        assertTrue("Did not throw exception", exception);
    }

    /**
     * @tests java.lang.String#String(byte[], int, int, int)
     */
    @SuppressWarnings("deprecation")
    public void test_Constructor$BIII() {
        // Test for method java.lang.String(byte [], int, int, int)
        String s = new String(new byte[] { 65, 66, 67, 68, 69 }, 0, 1, 3);
        assertTrue("Incorrect string returned: " + s, s.equals("BCD"));
        s = new String(new byte[] { 65, 66, 67, 68, 69 }, 1, 0, 5);
        assertTrue("Did not use nonzero hibyte", !s.equals("ABCDE"));
    }

    /**
     * @tests java.lang.String#String(byte[], int, int, java.lang.String)
     */
    public void test_Constructor$BIILjava_lang_String() throws Exception {
        // Test for method java.lang.String(byte [], int, int, java.lang.String)
        String s = null;
        s = new String(new byte[] { 65, 66, 67, 68, 69 }, 0, 5, "8859_1");
        assertTrue("Incorrect string returned: " + s, s.equals("ABCDE"));
        // Regression for HARMONY-1111
        assertNotNull(new String(new byte[] { (byte) 0xC0 }, 0, 1, "UTF-8"));
    }

    /**
     * @tests java.lang.String#String(byte[], java.lang.String)
     */
    public void test_Constructor$BLjava_lang_String() throws Exception {
        // Test for method java.lang.String(byte [], java.lang.String)
        String s = null;
        s = new String(new byte[] { 65, 66, 67, 68, 69 }, "8859_1");
        assertTrue("Incorrect string returned: " + s, s.equals("ABCDE"));
    }

    /**
     * @tests java.lang.String#String(char[])
     */
    public void test_Constructor$C() {
        // Test for method java.lang.String(char [])
        assertEquals("Failed Constructor test", "World", new String(buf));
    }

    /**
     * @tests java.lang.String#String(char[], int, int)
     */
    public void test_Constructor$CII() {
        // Test for method java.lang.String(char [], int, int)
        char[] buf = { 'H', 'e', 'l', 'l', 'o', 'W', 'o', 'r', 'l', 'd' };
        String s = new String(buf, 0, buf.length);
        assertTrue("Incorrect string created", hw1.equals(s));

        boolean exception = false;
        try {
            new String(new char[0], 0, Integer.MAX_VALUE);
        } catch (IndexOutOfBoundsException e) {
            exception = true;
        }
        assertTrue("Did not throw exception", exception);
    }

    /**
     * @tests java.lang.String#String(int[], int, int)
     */
    public void test_Constructor$III() {
        // Test for method java.lang.String(int [], int, int)
        try {
            new String(new int[0], 2, Integer.MAX_VALUE);
            fail("Did not throw exception");
        } catch (IndexOutOfBoundsException e) {
            // expected
        }
    }

    /**
     * @tests java.lang.String#String(java.lang.String)
     */
    public void test_ConstructorLjava_lang_String() {
        // Test for method java.lang.String(java.lang.String)
        String s = new String("Hello World");
        assertEquals("Failed to construct correct string", "Hello World", s);
    }

    /**
     * @tests java.lang.String#String(java.lang.StringBuffer)
     */
    public void test_ConstructorLjava_lang_StringBuffer() {
        // Test for method java.lang.String(java.lang.StringBuffer)
        StringBuffer sb = new StringBuffer();
        sb.append("HelloWorld");
        assertEquals("Created incorrect string", "HelloWorld", new String(sb));
    }

    /**
     * @tests java.lang.String#charAt(int)
     */
    public void test_charAtI() {
        // Test for method char java.lang.String.charAt(int)
        assertTrue("Incorrect character returned", hw1.charAt(5) == 'W'
                && (hw1.charAt(1) != 'Z'));
    }

    /**
     * @tests java.lang.String#compareTo(java.lang.String)
     */
    public void test_compareToLjava_lang_String() {
        // Test for method int java.lang.String.compareTo(java.lang.String)
        assertTrue("Returned incorrect value for first < second", "aaaaab"
                .compareTo("aaaaac") < 0);
        assertEquals("Returned incorrect value for first = second", 0, "aaaaac"
                .compareTo("aaaaac"));
        assertTrue("Returned incorrect value for first > second", "aaaaac"
                .compareTo("aaaaab") > 0);
        assertTrue("Considered case to not be of importance", !("A"
                .compareTo("a") == 0));

        try {
            "fixture".compareTo(null);
            fail("No NPE");
        } catch (NullPointerException e) {
        }
    }

    /**
     * @tests java.lang.String#compareToIgnoreCase(java.lang.String)
     */
    public void test_compareToIgnoreCaseLjava_lang_String() {
        // Test for method int
        // java.lang.String.compareToIgnoreCase(java.lang.String)
        assertTrue("Returned incorrect value for first < second", "aaaaab"
                .compareToIgnoreCase("aaaaac") < 0);
        assertEquals("Returned incorrect value for first = second", 0, "aaaaac"
                .compareToIgnoreCase("aaaaac"));
        assertTrue("Returned incorrect value for first > second", "aaaaac"
                .compareToIgnoreCase("aaaaab") > 0);
        assertEquals("Considered case to not be of importance", 0, "A"
                .compareToIgnoreCase("a"));

        assertTrue("0xbf should not compare = to 'ss'", "\u00df"
                .compareToIgnoreCase("ss") != 0);
        assertEquals("0x130 should compare = to 'i'", 0, "\u0130"
                .compareToIgnoreCase("i"));
        assertEquals("0x131 should compare = to 'i'", 0, "\u0131"
                .compareToIgnoreCase("i"));

        Locale defLocale = Locale.getDefault();
        try {
            Locale.setDefault(new Locale("tr", ""));
            assertEquals("Locale tr: 0x130 should compare = to 'i'", 0,
                    "\u0130".compareToIgnoreCase("i"));
            assertEquals("Locale tr: 0x131 should compare = to 'i'", 0,
                    "\u0131".compareToIgnoreCase("i"));
        } finally {
            Locale.setDefault(defLocale);
        }

        try {
            "fixture".compareToIgnoreCase(null);
            fail("No NPE");
        } catch (NullPointerException e) {
        }
    }

    /**
     * @tests java.lang.String#concat(java.lang.String)
     */
    public void test_concatLjava_lang_String() {
        // Test for method java.lang.String
        // java.lang.String.concat(java.lang.String)
        assertTrue("Concatenation failed to produce correct string", hello1
                .concat(world1).equals(hw1));
        boolean exception = false;
        try {
            String a = new String("test");
            String b = null;
            a.concat(b);
        } catch (NullPointerException e) {
            exception = true;
        }
        assertTrue("Concatenation failed to throw NP exception (1)", exception);
        exception = false;
        try {
            String a = new String("");
            String b = null;
            a.concat(b);
        } catch (NullPointerException e) {
            exception = true;
        }
        assertTrue("Concatenation failed to throw NP exception (2)", exception);

        String s1 = "";
        String s2 = "s2";
        String s3 = s1.concat(s2);
        assertEquals(s2, s3);
        // The RI returns a new string even when it's the same as the argument string.
        // assertNotSame(s2, s3);
        s3 = s2.concat(s1);
        assertEquals(s2, s3);
        // Neither Android nor the RI returns a new string when it's the same as *this*.
        // assertNotSame(s2, s3);

        s3 = s2.concat(s1);
        assertSame(s2, s3);
    }

    /**
     * @tests java.lang.String#copyValueOf(char[])
     */
    public void test_copyValueOf$C() {
        // Test for method java.lang.String java.lang.String.copyValueOf(char
        // [])
        char[] t = { 'H', 'e', 'l', 'l', 'o', 'W', 'o', 'r', 'l', 'd' };
        assertEquals("copyValueOf returned incorrect String", "HelloWorld",
                String.copyValueOf(t));
    }

    /**
     * @tests java.lang.String#copyValueOf(char[], int, int)
     */
    public void test_copyValueOf$CII() {
        // Test for method java.lang.String java.lang.String.copyValueOf(char
        // [], int, int)
        char[] t = { 'H', 'e', 'l', 'l', 'o', 'W', 'o', 'r', 'l', 'd' };
        assertEquals("copyValueOf returned incorrect String", "World", String
                .copyValueOf(t, 5, 5));
    }

    /**
     * @tests java.lang.String#endsWith(java.lang.String)
     */
    public void test_endsWithLjava_lang_String() {
        // Test for method boolean java.lang.String.endsWith(java.lang.String)
        assertTrue("Failed to fine ending string", hw1.endsWith("ld"));
    }

    /**
     * @tests java.lang.String#equals(java.lang.Object)
     */
    public void test_equalsLjava_lang_Object() {
        assertEquals("String not equal", hw1, hw2);
        assertEquals("Empty string equals check", "", "");
        assertEquals("Null string equals check", (String)null, (String)null);

        assertFalse("Unequal strings reports as equal", hw1.equals(comp11));
        assertFalse("Null string comparison failed", hw1.equals((String)null));
    }

    /**
     * @tests java.lang.String#equalsIgnoreCase(java.lang.String)
     */
    public void test_equalsIgnoreCaseLjava_lang_String() {
        // Test for method boolean
        // java.lang.String.equalsIgnoreCase(java.lang.String)
        assertTrue("lc version returned unequal to uc", hwlc
                .equalsIgnoreCase(hwuc));
    }

    /**
     * @tests java.lang.String#getBytes()
     */
    public void test_getBytes() {
        // Test for method byte [] java.lang.String.getBytes()
        byte[] sbytes = hw1.getBytes();

        for (int i = 0; i < hw1.length(); i++) {
            assertTrue("Returned incorrect bytes", sbytes[i] == (byte) hw1.charAt(i));
        }

        char[] chars = new char[1];
        for (int i = 0; i < 65536; i++) {
            // skip surrogates
            if (i == 0xd800)
                i = 0xe000;
            byte[] result = null;
            chars[0] = (char) i;
            String string = new String(chars);
            try {
                result = string.getBytes("8859_1");
                if (i < 256) {
                    assertEquals((byte) i, result[0]);
                } else {
                    /*
                     * Substitute character should be 0x1A [1], but may be '?'
                     * character. [1]
                     * http://en.wikipedia.org/wiki/Substitute_character
                     */
                    assertTrue(result[0] == '?' || result[0] == 0x1a);
                }
            } catch (java.io.UnsupportedEncodingException e) {
            }
            try {
                result = string.getBytes("UTF8");
                int length = i < 0x80 ? 1 : (i < 0x800 ? 2 : 3);
                assertTrue("Wrong length UTF8: " + Integer.toHexString(i),
                        result.length == length);
                assertTrue(
                        "Wrong bytes UTF8: " + Integer.toHexString(i),
                        (i < 0x80 && result[0] == i)
                                || (i >= 0x80
                                        && i < 0x800
                                        && result[0] == (byte) (0xc0 | ((i & 0x7c0) >> 6)) && result[1] == (byte) (0x80 | (i & 0x3f)))
                                || (i >= 0x800
                                        && result[0] == (byte) (0xe0 | (i >> 12))
                                        && result[1] == (byte) (0x80 | ((i & 0xfc0) >> 6)) && result[2] == (byte) (0x80 | (i & 0x3f))));
            } catch (java.io.UnsupportedEncodingException e) {
            }

            String bytes = null;
            try {
                bytes = new String(result, "UTF8");
                assertTrue("Wrong UTF8 byte length: " + bytes.length() + "("
                        + i + ")", bytes.length() == 1);
                assertTrue(
                        "Wrong char UTF8: "
                                + Integer.toHexString(bytes.charAt(0)) + " ("
                                + i + ")", bytes.charAt(0) == i);
            } catch (java.io.UnsupportedEncodingException e) {
            }
        }

        byte[] bytes = new byte[1];
        for (int i = 0; i < 256; i++) {
            bytes[0] = (byte) i;
            String result = null;
            try {
                result = new String(bytes, "8859_1");
                assertEquals("Wrong char length", 1, result.length());
                assertTrue("Wrong char value", result.charAt(0) == (char) i);
            } catch (java.io.UnsupportedEncodingException e) {
            }
        }
    }

    /**
     * @tests java.lang.String#getBytes(int, int, byte[], int)
     */
    @SuppressWarnings("deprecation")
    public void test_getBytesII$BI() {
        // Test for method void java.lang.String.getBytes(int, int, byte [],
        // int)
        byte[] buf = new byte[5];
        "Hello World".getBytes(6, 11, buf, 0);
        assertEquals("Returned incorrect bytes", "World", new String(buf));

        try {
            "Hello World".getBytes(-1, 1, null, 0);
            fail("Expected StringIndexOutOfBoundsException");
        } catch (StringIndexOutOfBoundsException e) {
        } catch (NullPointerException e) {
            fail("Threw wrong exception");
        }
    }

    /**
     * @tests java.lang.String#getBytes(java.lang.String)
     */
    public void test_getBytesLjava_lang_String() throws Exception {
        // Test for method byte [] java.lang.String.getBytes(java.lang.String)
        byte[] buf = "Hello World".getBytes();
        assertEquals("Returned incorrect bytes", "Hello World", new String(buf));

        try {
            "string".getBytes("8849_1");
            fail("No UnsupportedEncodingException");
        } catch (UnsupportedEncodingException e) {
        }

        byte[] bytes = "\u3048".getBytes("UTF-8");
        byte[] expected = new byte[] { (byte) 0xE3, (byte) 0x81, (byte) 0x88 };
        assertEquals(expected[0], bytes[0]);
        assertEquals(expected[1], bytes[1]);
        assertEquals(expected[2], bytes[2]);

        // Regression for HARMONY-663
        try {
            "string".getBytes("?Q?D??_??_6ffa?+vG?_??\u951f\ufffd??");
            fail("No UnsupportedEncodingException");
        } catch (UnsupportedEncodingException e) {
            // expected
        }

        // Regression for HARMONY-4135
        bytes = "-".getBytes("UTF-16");
        expected = new byte[] { -2, -1 };
        assertEquals(expected[0], bytes[0]);
        assertEquals(expected[1], bytes[1]);
    }

    /*
     * @tests java.lang.String#getBytes()
     */
    public void test_getBytes_NPE() throws Exception {
        try {
            "abc".getBytes((String) null);
            fail("Should throw NullPointerException");
        } catch (UnsupportedEncodingException whatTheRiDocumentsAndWeThrow) {
        } catch (NullPointerException whatTheRiActuallyThrows) {
        }

        try {
            "Hello World".getBytes(1, 2, null, 1);
            fail("Should throw NullPointerException");
        } catch (NullPointerException e) {
            // Expected
        }
    }

    /**
     * @tests java.lang.String#getChars(int, int, char[], int)
     */
    public void test_getCharsII$CI() {
        // Test for method void java.lang.String.getChars(int, int, char [],
        // int)
        hw1.getChars(5, hw1.length(), rbuf, 0);

        for (int i = 0; i < rbuf.length; i++)
            assertTrue("getChars returned incorrect char(s)", rbuf[i] == buf[i]);
    }

    /**
     * @tests java.lang.String#hashCode()
     */
    public void test_hashCode() {
        // Test for method int java.lang.String.hashCode()
        int hwHashCode = 0;
        final int hwLength = hw1.length();
        int powerOfThirtyOne = 1;
        for (int counter = hwLength - 1; counter >= 0; counter--) {
            hwHashCode += hw1.charAt(counter) * powerOfThirtyOne;
            powerOfThirtyOne *= 31;
        }
        assertEquals("String did not hash to correct value", hwHashCode, hw1.hashCode());
        assertEquals("The empty string \"\" did not hash to zero", 0, "".hashCode());
        assertEquals("Calculated wrong string hashcode", -1933545242, "Harmony".hashCode());
    }

    /**
     * @tests java.lang.String#indexOf(int)
     */
    public void test_indexOfI() {
        // Test for method int java.lang.String.indexOf(int)
        assertEquals("Invalid index returned", 1, hw1.indexOf('e'));
        assertEquals("Invalid index returned", 1, "a\ud800\udc00".indexOf(0x10000));
    }

    /**
     * @tests java.lang.String#indexOf(int, int)
     */
    public void test_indexOfII() {
        // Test for method int java.lang.String.indexOf(int, int)
        assertEquals("Invalid character index returned", 5, hw1.indexOf('W', 2));
        assertEquals("Invalid index returned", 2, "ab\ud800\udc00".indexOf(0x10000, 1));
    }

    /**
     * @tests java.lang.String#indexOf(java.lang.String)
     */
    public void test_indexOfLjava_lang_String() {
        // Test for method int java.lang.String.indexOf(java.lang.String)
        assertTrue("Failed to find string", hw1.indexOf("World") > 0);
        assertTrue("Failed to find string", !(hw1.indexOf("ZZ") > 0));
    }

    /**
     * @tests java.lang.String#indexOf(java.lang.String, int)
     */
    public void test_indexOfLjava_lang_StringI() {
        // Test for method int java.lang.String.indexOf(java.lang.String, int)
        assertTrue("Failed to find string", hw1.indexOf("World", 0) > 0);
        assertTrue("Found string outside index", !(hw1.indexOf("Hello", 6) > 0));
        assertEquals("Did not accept valid negative starting position", 0,
                hello1.indexOf("", -5));
        assertEquals("Reported wrong error code", 5, hello1.indexOf("", 5));
        assertEquals("Wrong for empty in empty", 0, "".indexOf("", 0));
    }

    /**
     * @tests java.lang.String#intern()
     */
    public void test_intern() {
        // Test for method java.lang.String java.lang.String.intern()
        assertTrue("Intern returned incorrect result", hw1.intern() == hw2
                .intern());
    }

    /**
     * @tests java.lang.String#lastIndexOf(int)
     */
    public void test_lastIndexOfI() {
        // Test for method int java.lang.String.lastIndexOf(int)
        assertEquals("Failed to return correct index", 5, hw1.lastIndexOf('W'));
        assertEquals("Returned index for non-existent char", -1, hw1
                .lastIndexOf('Z'));
        assertEquals("Failed to return correct index", 1, "a\ud800\udc00"
                .lastIndexOf(0x10000));
    }

    /**
     * @tests java.lang.String#lastIndexOf(int, int)
     */
    public void test_lastIndexOfII() {
        // Test for method int java.lang.String.lastIndexOf(int, int)
        assertEquals("Failed to return correct index", 5, hw1.lastIndexOf('W',
                6));
        assertEquals("Returned index for char out of specified range", -1, hw1
                .lastIndexOf('W', 4));
        assertEquals("Returned index for non-existent char", -1, hw1
                .lastIndexOf('Z', 9));

    }

    /**
     * @tests java.lang.String#lastIndexOf(java.lang.String)
     */
    public void test_lastIndexOfLjava_lang_String() {
        // Test for method int java.lang.String.lastIndexOf(java.lang.String)
        assertEquals("Returned incorrect index", 5, hw1.lastIndexOf("World"));
        assertEquals("Found String outside of index", -1, hw1
                .lastIndexOf("HeKKKKKKKK"));
    }

    /**
     * @tests java.lang.String#lastIndexOf(java.lang.String, int)
     */
    public void test_lastIndexOfLjava_lang_StringI() {
        // Test for method int java.lang.String.lastIndexOf(java.lang.String,
        // int)
        assertEquals("Returned incorrect index", 5, hw1.lastIndexOf("World", 9));
        int result = hw1.lastIndexOf("Hello", 2);
        assertTrue("Found String outside of index: " + result, result == 0);
        assertEquals("Reported wrong error code", -1, hello1
                .lastIndexOf("", -5));
        assertEquals("Did not accept valid large starting position", 5, hello1
                .lastIndexOf("", 5));
    }

    /**
     * @tests java.lang.String#length()
     */
    public void test_length() {
        // Test for method int java.lang.String.length()
        assertEquals("Invalid length returned", 11, comp11.length());
    }

    /**
     * @tests java.lang.String#regionMatches(int, java.lang.String, int, int)
     */
    public void test_regionMatchesILjava_lang_StringII() {
        // Test for method boolean java.lang.String.regionMatches(int,
        // java.lang.String, int, int)
        String bogusString = "xxcedkedkleiorem lvvwr e''' 3r3r 23r";

        assertTrue("identical regions failed comparison", hw1.regionMatches(2,
                hw2, 2, 5));
        assertTrue("Different regions returned true", !hw1.regionMatches(2,
                bogusString, 2, 5));
    }

    /**
     * @tests java.lang.String#regionMatches(boolean, int, java.lang.String,
     *        int, int)
     */
    public void test_regionMatchesZILjava_lang_StringII() {
        // Test for method boolean java.lang.String.regionMatches(boolean, int,
        // java.lang.String, int, int)

        String bogusString = "xxcedkedkleiorem lvvwr e''' 3r3r 23r";

        assertTrue("identical regions failed comparison", hw1.regionMatches(
                false, 2, hw2, 2, 5));
        assertTrue("identical regions failed comparison with different cases",
                hw1.regionMatches(true, 2, hw2, 2, 5));
        assertTrue("Different regions returned true", !hw1.regionMatches(true,
                2, bogusString, 2, 5));
        assertTrue("identical regions failed comparison with different cases",
                hw1.regionMatches(false, 2, hw2, 2, 5));
    }

    /**
     * @tests java.lang.String#replace(char, char)
     */
    public void test_replaceCC() {
        // Test for method java.lang.String java.lang.String.replace(char, char)
        assertEquals("Failed replace", "HezzoWorzd", hw1.replace('l', 'z'));
    }

    /**
     * @tests java.lang.String#replace(CharSequence, CharSequence)
     */
    public void test_replaceLjava_langCharSequenceLjava_langCharSequence() {
        assertEquals("Failed replace", "aaccdd", "aabbdd".replace(
                new StringBuffer("bb"), "cc"));
        assertEquals("Failed replace by bigger seq", "cccbccc", "aba".replace(
                "a", "ccc"));
        assertEquals("Failed replace by smaller seq", "$bba^", "$aaaaa^"
                .replace(new StringBuilder("aa"), "b"));
        assertEquals("Failed to replace empty string", "%%a%%b%%c%%",
                "abc".replace("", "%%"));
        assertEquals("Failed to replace with empty string", "aacc",
                "aabbcc".replace("b", ""));
        assertEquals("Failed to replace in empty string", "abc",
                "".replace("", "abc"));
    }

    /**
     * @tests java.lang.String#startsWith(java.lang.String)
     */
    public void test_startsWithLjava_lang_String() {
        // Test for method boolean java.lang.String.startsWith(java.lang.String)
        assertTrue("Failed to find string", hw1.startsWith("Hello"));
        assertTrue("Found incorrect string", !hw1.startsWith("T"));
    }

    /**
     * @tests java.lang.String#startsWith(java.lang.String, int)
     */
    public void test_startsWithLjava_lang_StringI() {
        // Test for method boolean java.lang.String.startsWith(java.lang.String,
        // int)
        assertTrue("Failed to find string", hw1.startsWith("World", 5));
        assertTrue("Found incorrect string", !hw1.startsWith("Hello", 5));
    }

    /**
     * @tests java.lang.String#substring(int)
     */
    public void test_substringI() {
        // Test for method java.lang.String java.lang.String.substring(int)
        assertEquals("Incorrect substring returned", "World", hw1.substring(5));
        assertTrue("not identical", hw1.substring(0) == hw1);
    }

    /**
     * @tests java.lang.String#substring(int, int)
     */
    public void test_substringII() {
        // Test for method java.lang.String java.lang.String.substring(int, int)
        assertTrue("Incorrect substring returned", hw1.substring(0, 5).equals(
                "Hello")
                && (hw1.substring(5, 10).equals("World")));
        assertTrue("not identical", hw1.substring(0, hw1.length()) == hw1);
    }

	/**
	 * @tests java.lang.String#substring(int, int)
	 */
	public void test_substringErrorMessage() {
		try {
			hw1.substring(-1, 1);
		} catch (StringIndexOutOfBoundsException ex) {
			String msg = ex.getMessage();
			assertTrue("Expected message to contain -1: " + msg, msg
			        .indexOf("-1") != -1);
		}
		try {
			hw1.substring(4, 1);
		} catch (StringIndexOutOfBoundsException ex) {
			String msg = ex.getMessage();
			assertTrue("Expected message to contain -3: " + msg, msg
			        .indexOf("-3") != -1);
		}
		try {
			hw1.substring(0, 100);
		} catch (StringIndexOutOfBoundsException ex) {
			String msg = ex.getMessage();
			assertTrue("Expected message to contain 100: " + msg, msg
			        .indexOf("100") != -1);
		}
	}

    /**
     * @tests java.lang.String#toCharArray()
     */
    public void test_toCharArray() {
        // Test for method char [] java.lang.String.toCharArray()

        String s = new String(buf, 0, buf.length);
        char[] schars = s.toCharArray();
        for (int i = 0; i < s.length(); i++)
            assertTrue("Returned incorrect char aray", buf[i] == schars[i]);
    }

    /**
     * @tests java.lang.String#toLowerCase()
     */
    public void test_toLowerCase() {
        // Test for method java.lang.String java.lang.String.toLowerCase()
        assertTrue("toLowerCase case conversion did not succeed", hwuc
                .toLowerCase().equals(hwlc));

        assertEquals(
                "a) Sigma has ordinary lower case value when isolated with Unicode 4.0",
                "\u03c3", "\u03a3".toLowerCase());
        assertEquals(
                "b) Sigma has final form lower case value at end of word with Unicode 4.0",
                "a\u03c2", "a\u03a3".toLowerCase());

        assertEquals("toLowerCase case conversion did not succeed",
        		"\uD801\uDC44", "\uD801\uDC1C".toLowerCase());
    }

    /**
     * @tests java.lang.String#toLowerCase(java.util.Locale)
     */
    public void test_toLowerCaseLjava_util_Locale() {
        // Test for method java.lang.String
        // java.lang.String.toLowerCase(java.util.Locale)
        assertTrue("toLowerCase case conversion did not succeed", hwuc
                .toLowerCase(java.util.Locale.getDefault()).equals(hwlc));
        assertEquals("Invalid \\u0049 for English", "\u0069", "\u0049"
                .toLowerCase(Locale.ENGLISH));
        assertEquals("Invalid \\u0049 for Turkish", "\u0131", "\u0049"
                .toLowerCase(new Locale("tr", "")));
    }

    /**
     * @tests java.lang.String#toString()
     */
    public void test_toString() {
        // Test for method java.lang.String java.lang.String.toString()
        assertTrue("Incorrect string returned", hw1.toString().equals(hw1));
    }

    /**
     * @tests java.lang.String#toUpperCase()
     */
    public void test_toUpperCase() {
        // Test for method java.lang.String java.lang.String.toUpperCase()
        assertTrue("Returned string is not UpperCase", hwlc.toUpperCase()
                .equals(hwuc));

        assertEquals("Wrong conversion", "SS", "\u00df".toUpperCase());

        String s = "a\u00df\u1f56";
        assertTrue("Invalid conversion", !s.toUpperCase().equals(s));

        assertEquals("toUpperCase case conversion did not succeed",
        		"\uD801\uDC1C", "\uD801\uDC44".toUpperCase());
    }

    /**
     * @tests java.lang.String#toUpperCase(java.util.Locale)
     */
    public void test_toUpperCaseLjava_util_Locale() {
        // Test for method java.lang.String
        // java.lang.String.toUpperCase(java.util.Locale)
        assertTrue("Returned string is not UpperCase", hwlc.toUpperCase()
                .equals(hwuc));
        assertEquals("Invalid \\u0069 for English", "\u0049", "\u0069"
                .toUpperCase(Locale.ENGLISH));
        assertEquals("Invalid \\u0069 for Turkish", "\u0130", "\u0069"
                .toUpperCase(new Locale("tr", "")));
    }

    /**
     * @tests java.lang.String#toUpperCase(java.util.Locale)
     */
    public void test_toUpperCaseLjava_util_Locale_subtest0() {
        // Test for method java.lang.String
        // java.lang.String.toUpperCase(java.util.Locale)
    }

    /**
     * @tests java.lang.String#trim()
     */
    public void test_trim() {
        // Test for method java.lang.String java.lang.String.trim()
        assertTrue("Incorrect string returned", " HelloWorld ".trim().equals(
                hw1));
    }

    /**
     * @tests java.lang.String#valueOf(char[])
     */
    public void test_valueOf$C() {
        // Test for method java.lang.String java.lang.String.valueOf(char [])
        assertEquals("Returned incorrect String", "World", String.valueOf(buf));
    }

    /**
     * @tests java.lang.String#valueOf(char[], int, int)
     */
    public void test_valueOf$CII() {
        // Test for method java.lang.String java.lang.String.valueOf(char [],
        // int, int)
        char[] t = { 'H', 'e', 'l', 'l', 'o', 'W', 'o', 'r', 'l', 'd' };
        assertEquals("copyValueOf returned incorrect String", "World", String
                .valueOf(t, 5, 5));
    }

    /**
     * @tests java.lang.String#valueOf(char)
     */
    public void test_valueOfC() {
        // Test for method java.lang.String java.lang.String.valueOf(char)
        for (int i = 0; i < 65536; i++)
            assertTrue("Incorrect valueOf(char) returned: " + i, String
                    .valueOf((char) i).charAt(0) == (char) i);
    }

    /**
     * @tests java.lang.String#valueOf(double)
     */
    public void test_valueOfD() {
        // Test for method java.lang.String java.lang.String.valueOf(double)
        assertEquals("Incorrect double string returned",
                "1.7976931348623157E308", String.valueOf(Double.MAX_VALUE));
    }

    /**
     * @tests java.lang.String#valueOf(float)
     */
    public void test_valueOfF() {
        // Test for method java.lang.String java.lang.String.valueOf(float)
        assertTrue("incorrect float string returned--got: "
                + String.valueOf(1.0F) + " wanted: 1.0", String.valueOf(1.0F)
                .equals("1.0"));
        assertTrue("incorrect float string returned--got: "
                + String.valueOf(0.9F) + " wanted: 0.9", String.valueOf(0.9F)
                .equals("0.9"));
        assertTrue("incorrect float string returned--got: "
                + String.valueOf(109.567F) + " wanted: 109.567", String
                .valueOf(109.567F).equals("109.567"));
    }

    /**
     * @tests java.lang.String#valueOf(int)
     */
    public void test_valueOfI() {
        // Test for method java.lang.String java.lang.String.valueOf(int)
        assertEquals("returned invalid int string", "1", String.valueOf(1));
    }

    /**
     * @tests java.lang.String#valueOf(long)
     */
    public void test_valueOfJ() {
        // Test for method java.lang.String java.lang.String.valueOf(long)
        assertEquals("returned incorrect long string", "927654321098", String
                .valueOf(927654321098L));
    }

    /**
     * @tests java.lang.String#valueOf(java.lang.Object)
     */
    public void test_valueOfLjava_lang_Object() {
        // Test for method java.lang.String
        // java.lang.String.valueOf(java.lang.Object)
        assertTrue("Incorrect Object string returned", obj.toString().equals(
                String.valueOf(obj)));
    }

    /**
     * @tests java.lang.String#valueOf(boolean)
     */
    public void test_valueOfZ() {
        // Test for method java.lang.String java.lang.String.valueOf(boolean)
        assertTrue("Incorrect boolean string returned", String.valueOf(false)
                .equals("false")
                && (String.valueOf(true).equals("true")));
    }

    /**
     * @tests java.lang.String#contentEquals(CharSequence cs)
     */
    public void test_contentEqualsLjava_lang_CharSequence() {
        // Test for method java.lang.String
        // java.lang.String.contentEquals(CharSequence cs)
        assertFalse("Incorrect result of compare", "qwerty".contentEquals(""));
    }

    /**
     * @tests java.lang.String#format(Locale, String, Object[])
     */
    @SuppressWarnings("boxing")
    public void test_format() {
        assertEquals("13% of sum is 0x11", String.format("%d%% of %s is 0x%x",
                13, "sum", 17));
        assertEquals("empty format", "", String.format("", 123, this));
        try {
            String.format(null);
            fail("NPE is expected on null format");
        } catch (NullPointerException ok) {
        }
    }
}