Elasticsearch之使用简单的增删改查(主键查询、条件查询和分页查询)操作(基于java的方式)

1.声明

当前内容用于本人学习和巩固Elasticsearch,当前的内容基于前面的安装和使用Elasticsearch操作，这里的内容为简单的使用java方式操作当前的Elasticsearch

2.准备操作

由于返回的响应为InputStream，所以需要解析流为String来进行输出
这里有一个小工具IOUtls

package com.hy.elasticsearch.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import java.nio.charset.Charset;

import org.apache.commons.codec.Charsets;

/**
 * @author hy
 * @description 通用的流工具
 */
public abstract class IOUtils {
	private static final int EOF = -1;
	private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

	public static void writeFile(final InputStream in, final OutputStream os) throws IOException {
		byte[] buffer = new byte[1024];
		int start = 0;
		try {
			while ((start = in.read(buffer)) != -1) {
				os.write(buffer, 0, start);
			}
		} catch (IOException e) {
			e.printStackTrace();
			throw e;
		} finally {
			closeStream(in);
			closeStream(os);
		}
	}

	public static void closeStream(final InputStream in) {
		if (in != null) {
			try {
				in.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	public static void closeStream(final OutputStream os) {
		if (os != null) {
			try {
				os.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	public static InputStream getInputStreamByFile(final File file) throws IOException {
		if (file.exists()) {
			if (file.isDirectory()) {
				throw new IOException("File '" + file + "' exists but is a directory");
			}
			if (file.canRead() == false) {
				throw new IOException("File '" + file + "' cannot be read");
			}
		} else {
			throw new FileNotFoundException("File '" + file + "' does not exist");
		}
		return new FileInputStream(file);
	}

	public static String toString(InputStream input) throws IOException {
		try {
			return toString(input, Charset.defaultCharset());
		} finally {
			closeStream(input);
		}

	}

	public static String toString(InputStream input, Charset encoding) throws IOException {
		StringBuilderWriter sw = new StringBuilderWriter();
		copy(input, sw, encoding);
		return sw.toString();
	}

	public static void copy(InputStream input, Writer output, Charset encoding) throws IOException {
		InputStreamReader in = new InputStreamReader(input, encoding);
		copy(in, output);
	}

	public static int copy(Reader input, Writer output) throws IOException {
		long count = copyLarge(input, output);
		if (count > Integer.MAX_VALUE) {
			return -1;
		}
		return (int) count;
	}

	public static long copyLarge(Reader input, Writer output) throws IOException {
		return copyLarge(input, output, new char[DEFAULT_BUFFER_SIZE]);
	}

	public static long copyLarge(Reader input, Writer output, char[] buffer) throws IOException {
		long count = 0;
		int n = 0;
		while (EOF != (n = input.read(buffer))) {
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}
}

以及一个StringBuilderWriter

package com.hy.elasticsearch.util;

import java.io.Serializable;
import java.io.Writer;

public class StringBuilderWriter extends Writer implements Serializable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private final StringBuilder builder;

	/**
	 * Construct a new {@link StringBuilder} instance with default capacity.
	 */
	public StringBuilderWriter() {
		this.builder = new StringBuilder();
	}

	/**
	 * Construct a new {@link StringBuilder} instance with the specified capacity.
	 *
	 * @param capacity The initial capacity of the underlying {@link StringBuilder}
	 */
	public StringBuilderWriter(int capacity) {
		this.builder = new StringBuilder(capacity);
	}

	/**
	 * Construct a new instance with the specified {@link StringBuilder}.
	 *
	 * @param builder The String builder
	 */
	public StringBuilderWriter(StringBuilder builder) {
		this.builder = builder != null ? builder : new StringBuilder();
	}

	/**
	 * Append a single character to this Writer.
	 *
	 * @param value The character to append
	 * @return This writer instance
	 */
	@Override
	public Writer append(char value) {
		builder.append(value);
		return this;
	}

	/**
	 * Append a character sequence to this Writer.
	 *
	 * @param value The character to append
	 * @return This writer instance
	 */
	@Override
	public Writer append(CharSequence value) {
		builder.append(value);
		return this;
	}

	/**
	 * Append a portion of a character sequence to the {@link StringBuilder}.
	 *
	 * @param value The character to append
	 * @param start The index of the first character
	 * @param end   The index of the last character + 1
	 * @return This writer instance
	 */
	@Override
	public Writer append(CharSequence value, int start, int end) {
		builder.append(value, start, end);
		return this;
	}

	/**
	 * Closing this writer has no effect.
	 */
	@Override
	public void close() {
	}

	/**
	 * Flushing this writer has no effect.
	 */
	@Override
	public void flush() {
	}

	/**
	 * Write a String to the {@link StringBuilder}.
	 * 
	 * @param value The value to write
	 */
	@Override
	public void write(String value) {
		if (value != null) {
			builder.append(value);
		}
	}

	/**
	 * Write a portion of a character array to the {@link StringBuilder}.
	 *
	 * @param value  The value to write
	 * @param offset The index of the first character
	 * @param length The number of characters to write
	 */
	@Override
	public void write(char[] value, int offset, int length) {
		if (value != null) {
			builder.append(value, offset, length);
		}
	}

	/**
	 * Return the underlying builder.
	 *
	 * @return The underlying builder
	 */
	public StringBuilder getBuilder() {
		return builder;
	}

	/**
	 * Returns {@link StringBuilder#toString()}.
	 *
	 * @return The contents of the String builder.
	 */
	@Override
	public String toString() {
		return builder.toString();
	}
}

3.按照主键查询

按照主键的查询操作

	final String ipAddress = "192.168.126.128";
	final int port = 9200;
	RestClient restClient;

	@Before
	public void init() {
		restClient = MyElasticsearchUtils.openElasticsearchWithHttp(ipAddress, port);
	}
	public void printResponseEntity(Response response) {

		try {
			System.out.println(response);
			HttpEntity entity = response.getEntity();
			InputStream is = entity.getContent();
			String result = IOUtils.toString(is);
			System.out.println(result);
		} catch (UnsupportedOperationException | IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

	// 测试查询数据,当查询一个不存在的文档的时候就会报错
	@Test
	public void testSelect() {
		Request request = new Request("GET", "/accounts/person/2");
		try {
			Response response = restClient.performRequest(request);
			printResponseEntity(response);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			MyElasticsearchUtils.closeClient(restClient);
		}
	}

执行结果

4.添加数据操作

// 添加数据操作
	@Test
	public void testInsert() {
		Request request = new Request("PUT", "/accounts/person/3");
		request.setJsonEntity("{\"user\":\"王五\",\"title\":\"工程师\",\"desc\":\"数据库管理\"}");
		try {
			Response response = restClient.performRequest(request);
			printResponseEntity(response);

		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			MyElasticsearchUtils.closeClient(restClient);
		}
	}

结果

5.修改数据操作

// 修改数据操作
	@Test
	public void testUpdate() {
		Request request = new Request("PUT", "/accounts/person/2");
		request.setJsonEntity("{\"user\":\"李四\",\"title\":\"java工程师2\",\"desc\":\"java数据库管理\"}");
		try {
			Response response = restClient.performRequest(request);
			printResponseEntity(response);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			MyElasticsearchUtils.closeClient(restClient);
		}
	}

结果

6.删除数据操作

@Test
	public void testDelete() {
		Request request = new Request("DELETE", "/accounts/person/3");
		// request.setJsonEntity("{\"user\":\"李四\",\"title\":\"java工程师\",\"desc\":\"java数据库管理\"}");
		try {
			Response response = restClient.performRequest(request);
			printResponseEntity(response);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			MyElasticsearchUtils.closeClient(restClient);
		}
	}

7.条件查询操作

// 使用条件查询
	@Test
	public void testSearchByCondition() {
		Request request = new Request("GET", "/accounts/person/_search");
		request.addParameter("q", "title:工程师");
		try {
			Response response = restClient.performRequest(request);
			printResponseEntity(response);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			MyElasticsearchUtils.closeClient(restClient);
		}
	}

结果

9.分页查询操作

@Test
	public void testSearchPageByCondition() {
		Request request = new Request("GET", "/accounts/person/_search");
		request.addParameter("q", "title:工程师");
		request.addParameter("from", "1");
		request.addParameter("size", "1");
		try {
			Response response = restClient.performRequest(request);
			printResponseEntity(response);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			MyElasticsearchUtils.closeClient(restClient);
		}
	}

由于这里数据比较少，所以默认查询第二条

10.总结

1.使用java方式操作Elasticsearch,对应的添加就是PUT,修改也是PUT,删除为DELETE,查询为GET

2.添加和修改数据的时候可以指定JSONBODY,这样就添加了json数据了

3.查询的时候可以使用_search和指定parameter的key为q,值为字段=某个值,可以实现条件查询，如果添加from和size就可以实现分页了

4.删除和主键查询操作时如果主键id不存在，则引发异常！

以上纯属个人见解，如有问题请联系本人！