如果未定义toString,则
Java使用一些哈希打印类名.如果定义了toString,如何实现此功能？
package tests.java.lang;
public class Try_ToString {
public static class MyClass {
protected int value;
public MyClass(int value) {
this.value = value;
}
}
public static class MyClass2 extends MyClass {
public MyClass2(int value) {
super(value);
}
@Override
public String toString() {
return String.valueOf(value);
}
}
public static void main(String[] args) {
MyClass a = new MyClass(12);
MyClass b = new MyClass2(12);
System.out.println("a = " + a.toString());
System.out.println("b = " + b.toString());
}
}
解决方法
默认的toString实现只是将对象的类名“@”与其十六进制的hashCode连接起来.
public static String defaultToString(Object o) {
return o.getClass().getName() + "@" + Integer.toHexString(o.hashCode());
}