用String的equals方法比较一个StringBuffer的内容是否相等?
如下代码中str   与   buffer中的内容都是Java，为什么却输出Both   are   not   equal.

String   str   =   "Java ";  
StringBuffer   buffer   =   new   StringBuffer(str);  
if(str.equals(buffer)){  
System.out.println( "Both   are   equal ");  
}else{  
System.out.println( "Both   are   not   equal ");  
}


------解决方案--------------------

public boolean equals(Object anObject) {
if (this == anObject) {
return true;
}
if (anObject instanceof String) { //注意这儿
String anotherString = (String)anObject;
int n = count;
if (n == anotherString.count) {
char v1[] = value;
char v2[] = anotherString.value;
int i = offset;
int j = anotherString.offset;
while (n-- != 0) {
if (v1[i++] != v2[j++])
return false;
}
return true;
}
}
return false;
}
------解决方案--------------------
一个String ，一个StringBuffer，你比个啥啊

str.equals(buffer.toString()) 肯定返回true