Java 比较两个HashMap里的数据是否一致

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u014514528/article/details/73946281

开发中，可能会遇到两个HashMap内容的比较，如果一一去遍历比较的话，可能造成资源的浪费。现可以采用一下方法：

一.比较两个HashMap<String,TestBean> 内容是否一致

1.首先创建一个TestBean实体，记得重写hashCode  和  equals 方法。

package com.wxd.test;

public class TestBean {
	private String id = "";
	private String dc = "";
	private String status = "";
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getDc() {
		return dc;
	}
	public void setDc(String dc) {
		this.dc = dc;
	}
	public String getStatus() {
		return status;
	}
	public void setStatus(String status) {
		this.status = status;
	}
	@Override
	public String toString() {
		return "TestBean [id=" + id + ", dc=" + dc + ", status=" + status + "]";
	}
	public TestBean(String id, String dc, String status) {
		super();
		this.id = id;
		this.dc = dc;
		this.status = status;
	}
	public TestBean() {
		super();
		// TODO Auto-generated constructor stub
	}
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((dc == null) ? 0 : dc.hashCode());
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		result = prime * result + ((status == null) ? 0 : status.hashCode());
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		TestBean other = (TestBean) obj;
		if (dc == null) {
			if (other.dc != null)
				return false;
		} else if (!dc.equals(other.dc))
			return false;
		if (id == null) {
			if (other.id != null)
				return false;
		} else if (!id.equals(other.id))
			return false;
		if (status == null) {
			if (other.status != null)
				return false;
		} else if (!status.equals(other.status))
			return false;
		return true;
	}
	
}

2.进行比较

	TestBean t1 = new TestBean("1", "1", "1");
	TestBean t2 = new TestBean("1", "1", "1");
	HashMap<String,TestBean> map1 = new HashMap();
	HashMap<String,TestBean> map2 = new HashMap();
	map1.put("1", t1);
	map2.put("1", t2);
	System.out.println(map1.equals(map2));

输出为 true

	TestBean t1 = new TestBean("1", "2", "1");
	TestBean t2 = new TestBean("1", "1", "1");
	HashMap<String,TestBean> map1 = new HashMap();
	HashMap<String,TestBean> map2 = new HashMap();
	map1.put("1", t1);
	map2.put("1", t2);
	System.out.println(map1.equals(map2));

输出为false

	TestBean t1 = new TestBean("1", "2", "1");
	TestBean t2 = new TestBean("1", "1", "1");
	TestBean t3 = new TestBean("1", "1", "1");
	
	HashMap<String,TestBean> map1 = new HashMap();
	HashMap<String,TestBean> map2 = new HashMap();
	map1.put("1", t1);
	map1.put("2", t3);
	map2.put("1", t2);
	System.out.println(map1.equals(map2));

输出为false

二、比较两个HashMap 中嵌套map

		HashMap<String,String> tmap1 =  new HashMap();
		HashMap<String,String> tmap2 =  new HashMap();
		tmap1.put("1", "1");
		tmap2.put("1", "1");
		tmap1.put("2", "1");
		HashMap<String,HashMap<String,String>> map1 = new HashMap();
		HashMap<String,HashMap<String,String>> map2 = new HashMap();
		map1.put("1", tmap1);
		map2.put("1", tmap2);
		System.out.println(map1.equals(map2));

输出为false

	HashMap<String,String> tmap1 =  new HashMap();
		HashMap<String,String> tmap2 =  new HashMap();
		tmap1.put("1", "1");
		tmap2.put("1", "1");
	//	tmap1.put("2", "1");
		HashMap<String,HashMap<String,String>> map1 = new HashMap();
		HashMap<String,HashMap<String,String>> map2 = new HashMap();
		map1.put("1", tmap1);
		map2.put("1", tmap2);
		System.out.println(map1.equals(map2));

输出为true

因为开发需要，只测试了这两种情况。