如何实现一个字符串类？？

老师让我自己编写String的一些方法，让后实现一个字符串类，结果我只是把编写的那些方法放在一个类里面了，老师说不可以，他不让用String的原有方法，还要有什么构造函数，谁能给出一些思路啊，解释一下什么意思啊？？ string --------------------编程问答-------------------- 不知道你说的抽象，还是你老是说的抽象。
String应该是不能继承的，
StringBuffer应该可以。
要是我继承一个StringBuffer，然后任务完成。 --------------------编程问答-------------------- 主要就是对String的方法自己从新编写，实现一个字符串类，字符串类是怎么实现的？？？ --------------------编程问答-------------------- 就是重写String类的方法，这个简单，你看那些方法都是来实现什么方法，你就重写这个方法名，在这个方法里自己写要来实现的功能，只要是重写！！！ --------------------编程问答-------------------- 看看String的源码就明白了 --------------------编程问答-------------------- 已经重写完了，然后我把这些一堆的函数全放在一个类里面了，老师说不行，他说让我实现的是一个字符串类~~这我就不太明白怎么弄了，给点思路啊………… --------------------编程问答-------------------- 不让用原生的String类,那就是让你们自己实现一个String类吧?你看原来的怎么写的,就用自己的代码重写一下吧.. --------------------编程问答-------------------- 他的意思可能谁叫你override String方法 --------------------编程问答-------------------- 先去看看api吧，。、。http://www.ostools.net/apidocs/apidoc?api=jdk-zh

源码可以在jdk里面找到...

eclipse上面弄的。 --------------------编程问答-------------------- 给你把java.lang.String简化一下
MyString类：
public class MyString implements MyCharSequence{
/** The value is used for character storage. */
private final char value[];

/** The offset is the first index of the storage that is used. */
private final int offset;

/** The count is the number of characters in the String. */
private final int count;

public MyString() {
this.offset = 0;
this.count = 0;
this.value = new char[0];
}

// Package private constructor which shares value array for speed.
 MyString(int offset, int count, char value[]) {
this.value = value;
this.offset = offset;
this.count = count;
 }

/**
 * Returns the length of this string.
 * The length is equal to the number of <a href="Character.html#unicode">Unicode
 * code units</a> in the string.
 *
 * @return the length of the sequence of characters represented by this
 * object.
 */
@Override
 public int length() {
 return count;
 }

/**
 * Returns the <code>char</code> value at the
 * specified index. An index ranges from <code>0</code> to
 * <code>length() - 1</code>. The first <code>char</code> value of the sequence
 * is at index <code>0</code>, the next at index <code>1</code>,
 * and so on, as for array indexing.
 *
 * If the <code>char</code> value specified by the index is a
 * <a href="Character.html#unicode">surrogate</a>, the surrogate
 * value is returned.
 *
 * @param index the index of the <code>char</code> value.
 * @return the <code>char</code> value at the specified index of this string.
 * The first <code>char</code> value is at index <code>0</code>.
 * @exception IndexOutOfBoundsException if the <code>index</code>
 * argument is negative or not less than the length of this
 * string.
 */
@Override
 public char charAt(int index) {
 if ((index < 0) || (index >= count)) {
 throw new StringIndexOutOfBoundsException(index);
 }
 return value[index + offset];
 }

/**
 * Returns a new string that is a substring of this string. The
 * substring begins at the specified <code>beginIndex</code> and
 * extends to the character at index <code>endIndex - 1</code>.
 * Thus the length of the substring is <code>endIndex-beginIndex</code>.
 * 
 * Examples:
 * <blockquote><pre>
 * "hamburger".substring(4, 8) returns "urge"
 * "smiles".substring(1, 5) returns "mile"
 * </pre></blockquote>
 *
 * @param beginIndex the beginning index, inclusive.
 * @param endIndex the ending index, exclusive.
 * @return the specified substring.
 * @exception IndexOutOfBoundsException if the
 * <code>beginIndex</code> is negative, or
 * <code>endIndex</code> is larger than the length of
 * this <code>String</code> object, or
 * <code>beginIndex</code> is larger than
 * <code>endIndex</code>.
 */
 public MyString substring(int beginIndex, int endIndex) {
if (beginIndex < 0) {
 throw new StringIndexOutOfBoundsException(beginIndex);
}
if (endIndex > count) {
 throw new StringIndexOutOfBoundsException(endIndex);
}
if (beginIndex > endIndex) {
 throw new StringIndexOutOfBoundsException(endIndex - beginIndex);
}
return ((beginIndex == 0) && (endIndex == count)) ? this :
 new MyString(offset + beginIndex, endIndex - beginIndex, value);
 }

 /**
 * Returns a new character sequence that is a subsequence of this sequence.
 *
 * An invocation of this method of the form
 *
 * <blockquote><pre>
 * str.subSequence(begin, end)</pre></blockquote>
 *
 * behaves in exactly the same way as the invocation
 *
 * <blockquote><pre>
 * str.substring(begin, end)</pre></blockquote>
 *
 * This method is defined so that the <tt>String</tt> class can implement
 * the {@link CharSequence} interface. 
 *
 * @param beginIndex the begin index, inclusive.
 * @param endIndex the end index, exclusive.
 * @return the specified subsequence.
 *
 * @throws IndexOutOfBoundsException
 * if <tt>beginIndex</tt> or <tt>endIndex</tt> are negative,
 * if <tt>endIndex</tt> is greater than <tt>length()</tt>,
 * or if <tt>beginIndex</tt> is greater than <tt>startIndex</tt>
 *
 * @since 1.4
 * @spec JSR-51
 */
 public MyCharSequence subSequence(int beginIndex, int endIndex) {
 return this.substring(beginIndex, endIndex);
 }
}

MyCharSequence接口：定义我要生成的字符串类的基本操作
public interface MyCharSequence {

 /**
 * Returns the length of this character sequence. The length is the number
 * of 16-bit <code>char</code>s in the sequence.
 *
 * @return the number of <code>char</code>s in this sequence
 */
 int length();

 /**
 * Returns the <code>char</code> value at the specified index. An index ranges from zero
 * to <tt>length() - 1</tt>. The first <code>char</code> value of the sequence is at
 * index zero, the next at index one, and so on, as for array
 * indexing. 
 *
 * If the <code>char</code> value specified by the index is a
 * <a href="Character.html#unicode">surrogate</a>, the surrogate
 * value is returned.
 *
 * @param index the index of the <code>char</code> value to be returned
 *
 * @return the specified <code>char</code> value
 *
 * @throws IndexOutOfBoundsException
 * if the <tt>index</tt> argument is negative or not less than
 * <tt>length()</tt>
 */
 char charAt(int index);

 /**
 * Returns a new <code>CharSequence</code> that is a subsequence of this sequence.
 * The subsequence starts with the <code>char</code> value at the specified index and
 * ends with the <code>char</code> value at index <tt>end - 1</tt>. The length
 * (in <code>char</code>s) of the
 * returned sequence is <tt>end - start</tt>, so if <tt>start == end</tt>
 * then an empty sequence is returned. 
 *
 * @param start the start index, inclusive
 * @param end the end index, exclusive
 *
 * @return the specified subsequence
 *
 * @throws IndexOutOfBoundsException
 * if <tt>start</tt> or <tt>end</tt> are negative,
 * if <tt>end</tt> is greater than <tt>length()</tt>,
 * or if <tt>start</tt> is greater than <tt>end</tt>
 */
 MyCharSequence subSequence(int start, int end);

 /**
 * Returns a string containing the characters in this sequence in the same
 * order as this sequence. The length of the string will be the length of
 * this sequence. 
 *
 * @return a string consisting of exactly this sequence of characters
 */
 public String toString();

}

--------------------编程问答-------------------- 意思就是你自己写代码实现String类的功能，比如String类有一个方法toUpperCase()，功能是把字符串转化为大写；你需要自己去实现他，而不是用线程的方法。
--------------------编程问答-------------------- 意思就是你自己写代码实现String类的功能，比如String类有一个方法toUpperCase()，功能是把字符串转化为大写；你需要自己去实现他，而不是用现成的方法。

补充：Java ,  Java SE

如何实现一个 字符串类 ？？

如何实现一个字符串类？？