1、创建测试类(TestMap1.java)
package com.jeff;
import java.util.HashMap;
import java.util.Map;
public class TestMap1 {
public static void main(String[] args) {
Map<String, Object> map = new HashMap<String, Object>();
map.put("str", "Jeff");
map.put("int", Integer.MAX_VALUE);
map.put("long", Long.MAX_VALUE);
map.put("float", Float.MAX_VALUE);
map.put("double", Double.MAX_VALUE);
map.put("u", new User("Jeff", "123456"));
map.forEach((key, value) -> {
if (value instanceof String) {
System.out.println("String类型-->" + key + ":" + value);
} else if (value instanceof Integer) {
System.out.println("Integer类型-->" + key + ":" + value);
} else if (value instanceof Long) {
System.out.println("Long类型-->" + key + ":" + value);
} else if (value instanceof Float) {
System.out.println("Float类型-->" + key + ":" + value);
} else if (value instanceof Double) {
System.out.println("Double类型-->" + key + ":" + value);
} else if (value instanceof User) {
System.out.println("User类型-->" + key + ":" + value);
}
});
}
}
class User {
private String userName;
private String password;
public User(String userName, String password) {
super();
this.userName = userName;
this.password = password;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public String toString() {
return "User [userName=" + userName + ", password=" + password + "]";
}
}
2、控制台输出结果