Java中字符串反转

public void convertStr(String str){
//将String 对象转换为可改变的StringBuffer类对象
//然后调用StringBuffer类的reverse()方法实现反转
String strReverse=new StringBuffer(str).reverse().toString();
System.out.println(strReverse);

}

public void convertStr(String str){

for (int i=str.length()-1;i>=0;i--)
{
//每次倒序输出一个字符
System.out.print(str.charAt(i));
}
}

public  void convertStr(String str){

String strNew="";
String [] s=new String[str.length()];
for (int x=0;x<str.length();x++ )
{
s[x]=str.substring(x,x+1);
}
for (int x=str.length()-1;x>=0;x-- )
{
strNew+=s[x];
}
System.out.println(strNew);
}