java两个对象实体类字段值进行对比,以一个为基准,不同则进行更新操作,插入ES索引,代码样例demo...
时间: 2024-03-09 08:51:05 浏览: 15
假设有两个实体类 `EntityA` 和 `EntityB`,它们都有相同的字段,我们以 `EntityA` 为基准进行对比和更新操作。
1. 首先,我们可以利用 Java 的反射机制获取 `EntityA` 和 `EntityB` 的所有字段和值。
```java
Field[] fields = EntityA.class.getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
Object valueA = field.get(entityA);
Object valueB = field.get(entityB);
// TODO: 进行字段值的对比和更新操作
}
```
2. 对比两个字段值是否相同,如果不同则进行更新操作。
```java
if (!Objects.equals(valueA, valueB)) {
field.set(entityA, valueB);
}
```
3. 对于更新了的 `EntityA` 对象,我们可以将其插入到 ES 索引中。
```java
IndexRequest request = new IndexRequest("index_name");
request.id(entityA.getId());
request.source(entityA.toJsonString(), XContentType.JSON);
IndexResponse response = client.index(request, RequestOptions.DEFAULT);
```
完整的代码样例如下所示:
```java
import org.apache.http.HttpHost;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import java.lang.reflect.Field;
import java.util.Objects;
public class EntityComparisonDemo {
private static RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
new HttpHost("localhost", 9200, "http")
));
public static void main(String[] args) throws Exception {
EntityA entityA = new EntityA("1", "John", 20);
EntityB entityB = new EntityB("1", "Mary", 21);
Field[] fields = EntityA.class.getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
Object valueA = field.get(entityA);
Object valueB = field.get(entityB);
if (!Objects.equals(valueA, valueB)) {
field.set(entityA, valueB);
}
}
IndexRequest request = new IndexRequest("index_name");
request.id(entityA.getId());
request.source(entityA.toJsonString(), XContentType.JSON);
IndexResponse response = client.index(request, RequestOptions.DEFAULT);
client.close();
}
static class EntityA {
private String id;
private String name;
private int age;
public EntityA(String id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
}
public String getId() {
return id;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
public String toJsonString() {
return String.format("{\"id\":\"%s\",\"name\":\"%s\",\"age\":%d}", id, name, age);
}
}
static class EntityB {
private String id;
private String name;
private int age;
public EntityB(String id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
}
public String getId() {
return id;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
}
}
```