mystringbuffer.java

关于数据结构的JAVA源代码

public class MyStringBuffer{
	private char[] value;
	private int count;
	

	public MyStringBuffer(String str){
		char[] chararray=str.toCharArray();
		value = chararray;
		count = chararray.length;
	
	}
	
	private void expandCapacity(int minCapacity){
	   int newCapacity = value.length * 2;
       if (minCapacity > newCapacity) {
	        newCapacity = minCapacity;
	    }	
	   char newValue[] = new char[newCapacity];
	   arrayCopy(value, 0, newValue, 0, count);
	   value = newValue;	//
	}

	
	private static void arrayCopy(char[] src,int srcPos,char[] dst,int dstPos,int length){
    	if(src.length-srcPos<length||dst.length-dstPos<length)
    	   throw new StringIndexOutOfBoundsException(length);
    	for(int i=0;i<length;i++){
    		dst[dstPos++] = src[srcPos++];
    	}
    }
    
    public static void stringCopy(MyStringBuffer src,int srcPos,MyStringBuffer dst,int dstPos,int length){
    	arrayCopy(src.toArray(),srcPos,dst.toArray(),dstPos,length);
    }
    
    public MyStringBuffer concat(MyStringBuffer str) {
	    int otherLen = str.length();
	    if (otherLen == 0) {
	       return this;
	    }
	    expandCapacity(count + otherLen);	    
	    stringCopy(str,0,this,count,str.length());
	    count=count+otherLen;    
	    return this;				//
    }     
    public char[] toArray(){
    	return value;
    }    
   
    public int length() {
        return count;
    }      
    
    public void myPrint(){
    	for(int i=0;i<count;i++){
    		System.out.print(value[i]);
    	}
    	System.out.println();
    }
}