Record some problems and the overall process that arise in the process of using java to call the hugegraph graph database. (The code sample is posted at the bottom)
Official website: https://hugegraph.apache.org/docs/clients/restful-api/propertykey/
Java can be called in two ways
: 1. One is the official API interface, which can Directly call the restful interface;
the following is an example of a postman call: note that the graph database (hugegraph) account and password need to be verified;
2. It can be called through the java client tool provided by hugegraph: and the official website provides calling examples;
problems encountered during the process:
1 , the jar package referenced by hugegraph conflicts with the fastJSon jar package, you can reduce the fastJSon version to 1.1
. jaxrs.FastJsonAutoDiscoverable FastJsonAutoDiscoverable = null;
static { FastJsonAutoDiscoverable.autoDiscover = false; } 2. Hugegraph will return an exception information string in many cases, and the returned information cannot be parsed. Solution: Customize the exception information class ReturnErrorJsonHandler and reset the message information.
The overall code demo is posted below:
1. HugeGraphUtils (graph database interface API)
package net.beidousky.web.app.utils;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.JSONPath;
import net.beidousky.web.app.domain.Result;
import net.beidousky.web.app.entity.HugeClientVo;
import org.springframework.core.io.ClassPathResource;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Properties;
/**
* 图数据库接口API(hugegraph)
*/
public class HugeGraphUtils {
//解决fastJSon与Jersey冲突问题
private static final com.alibaba.fastjson.support.jaxrs.FastJsonAutoDiscoverable FastJsonAutoDiscoverable = null;
static {
FastJsonAutoDiscoverable.autoDiscover = false;
}
/**
* 获取hugeGraph客户端操作对象
* @param key
* @return
* @throws IOException
*/
private static HugeClientVo getHugeGraph(String key) throws IOException {
//读取配置文件hugeGraph连接信息
ClassPathResource classPathResource = new ClassPathResource("hugeGraph.properties");
Properties properties = new Properties();
properties.load(classPathResource.getInputStream());
//读取配置文件中key对应的value值
String json = new String (properties.getProperty(key).getBytes(StandardCharsets.UTF_8), StandardCharsets.UTF_8) ;
HugeClientVo hugeClientVo =JSON.parseObject(json,HugeClientVo.class);
return hugeClientVo;
}
/**
* 属性操作--创建属性
* @param falg
* @return
* @throws IOException
*/
public static Result createPropertyKey(String falg,String json) throws IOException{
HugeClientVo hugeClientVo = getHugeGraph(falg);
String ip = hugeClientVo.getIp();
String userName =hugeClientVo.getUserName();
String password =hugeClientVo.getPassword();
String url = ip+ "/graphs/hugegraph/schema/propertykeys" ;
String res = "";
try{
res = RestTemplateUtil.hugeGraphRest(json,url,userName,password);
}catch(Exception e){
String message = JSONPath.read(e.getMessage(),"$.message",String.class);
Result result = Result.success(message);
return result;
}
int id = JSONPath.read(res,"$.id",int.class);
JSONObject jsonObject = new JSONObject();
jsonObject.put("id",id);
Result result = new Result(10000,"属性创建成功",jsonObject);
return result;
}
/**
* 属性操作--检查属性信息是否存在
* @param falg
* @return
* @throws IOException
*/
public static Result getPropertyKey(String falg,String name) throws IOException{
HugeClientVo hugeClientVo = getHugeGraph(falg);
String ip = hugeClientVo.getIp();
String userName =hugeClientVo.getUserName();
String password =hugeClientVo.getPassword();
String url = ip+ "/graphs/hugegraph/schema/propertykeys/"+name;
String res = RestTemplateUtil.hugeGraphGet(url,userName,password);
int id = JSONPath.read(res,"$.id",int.class);
JSONObject jsonObject = new JSONObject();
jsonObject.put("id",id);
Result result = new Result(10000,"属性创建成功",jsonObject);
return result;
}
/**
* 获取所有顶点标签
* @param falg
* @return
* @throws IOException
*/
/* public static String getAllLabel(String falg) throws IOException, SQLException, JSONException {
HugeClient hugeClient = getHugeClient(falg);
GremlinManager gremlin = hugeClient.gremlin();
ResultSet resultSet = gremlin.gremlin("g.V()").execute();
List<Object> list = resultSet.data();
System.out.print(resultSet);
JSONArray jsonarray = JSONArray.fromObject(list);
return jsonarray.toString();
}
*/
}
2. HugeClientUtils (java operation graph database client)
package net.beidousky.web.app.utils;
import com.alibaba.fastjson.JSON;
import com.baidu.hugegraph.driver.GremlinManager;
import com.baidu.hugegraph.driver.HugeClient;
import com.baidu.hugegraph.driver.SchemaManager;
import com.baidu.hugegraph.structure.gremlin.ResultSet;
import com.baidu.hugegraph.structure.schema.PropertyKey;
import net.beidousky.web.app.entity.HugeClientVo;
import net.beidousky.web.app.entity.hugegraph.Property;
import net.sf.json.JSONArray;
import org.json.JSONException;
import org.springframework.core.io.ClassPathResource;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.sql.SQLException;
import java.util.List;
import java.util.Properties;
/**
* java操作图数据库(hugeGraph)
*/
public class HugeClientUtils {
//解决fastJSon与Jersey冲突问题
private static final com.alibaba.fastjson.support.jaxrs.FastJsonAutoDiscoverable FastJsonAutoDiscoverable = null;
static {
FastJsonAutoDiscoverable.autoDiscover = false;
}
/**
* 获取hugeGraph客户端操作对象
* @param key
* @return
* @throws IOException
*/
private static HugeClient getHugeClient(String key) throws IOException {
//读取配置文件hugeGraph连接信息
ClassPathResource classPathResource = new ClassPathResource("hugeGraph.properties");
Properties properties = new Properties();
properties.load(classPathResource.getInputStream());
//读取配置文件中key对应的value值
String json = new String (properties.getProperty(key).getBytes(StandardCharsets.UTF_8), StandardCharsets.UTF_8) ;
HugeClientVo hugeClientVo =JSON.parseObject(json,HugeClientVo.class);
HugeClient hugeClient = null;
if(hugeClientVo!=null){
//获取操作客户端
System.out.print("ip:"+hugeClientVo.getIp()+",name:"+hugeClientVo.getHugegraphGraphName()+",username:"+hugeClientVo.getUserName()+",password:"+hugeClientVo.getPassword());
hugeClient = HugeClient.builder(hugeClientVo.getIp(),hugeClientVo.getHugegraphGraphName())
.configUser(hugeClientVo.getUserName(),hugeClientVo.getPassword())
.build();
}
return hugeClient;
}
/**
* 属性操作--创建属性
* @param falg
* @return
* @throws IOException
*/
public static String createPropertyKey(String falg, Property property) throws IOException, SQLException, JSONException {
HugeClient hugeClient = getHugeClient(falg);
SchemaManager schema = hugeClient.schema();
PropertyKey res = null;
switch (property.getData_type()){
case "STRING" :
switch (property.getCardinality()){
case "SINGLE" :
res = schema.propertyKey(property.getName()).asText().valueSingle().ifNotExist().create();
case "LIST" :
res = schema.propertyKey(property.getName()).asText().valueList().ifNotExist().create();
case "SET" :
res = schema.propertyKey(property.getName()).asText().valueSet().ifNotExist().create();
}
break;
case "INT" :
switch (property.getCardinality()){
case "SINGLE" :
res = schema.propertyKey(property.getName()).asInt().valueSingle().ifNotExist().create();
case "LIST" :
res = schema.propertyKey(property.getName()).asInt().valueList().ifNotExist().create();
case "SET" :
res = schema.propertyKey(property.getName()).asInt().valueSet().ifNotExist().create();
}
break;
case "FLOAT" :
switch (property.getCardinality()){
case "SINGLE" :
res = schema.propertyKey(property.getName()).asFloat().valueSingle().ifNotExist().create();
case "LIST" :
res = schema.propertyKey(property.getName()).asFloat().valueList().ifNotExist().create();
case "SET" :
res = schema.propertyKey(property.getName()).asFloat().valueSet().ifNotExist().create();
}
break;
case "DATE" :
switch (property.getCardinality()){
case "SINGLE" :
res = schema.propertyKey(property.getName()).asDate().valueSingle().ifNotExist().create();
case "LIST" :
res = schema.propertyKey(property.getName()).asDate().valueList().ifNotExist().create();
case "SET" :
res = schema.propertyKey(property.getName()).asDate().valueSet().ifNotExist().create();
}
break;
case "BOOLEAN" :
switch (property.getCardinality()){
case "SINGLE" :
res = schema.propertyKey(property.getName()).asBoolean().valueSingle().ifNotExist().create();
case "LIST" :
res = schema.propertyKey(property.getName()).asBoolean().valueList().ifNotExist().create();
case "SET" :
res = schema.propertyKey(property.getName()).asBoolean().valueSet().ifNotExist().create();
}
break;
case "BLOB" :
switch (property.getCardinality()){
case "SINGLE" :
res = schema.propertyKey(property.getName()).asBlob().valueSingle().ifNotExist().create();
case "LIST" :
res = schema.propertyKey(property.getName()).asBlob().valueList().ifNotExist().create();
case "SET" :
res = schema.propertyKey(property.getName()).asBlob().valueSet().ifNotExist().create();
}
case "Double" :
switch (property.getCardinality()){
case "SINGLE" :
res = schema.propertyKey(property.getName()).asDouble().valueSingle().ifNotExist().create();
case "LIST" :
res = schema.propertyKey(property.getName()).asDouble().valueList().ifNotExist().create();
case "SET" :
res = schema.propertyKey(property.getName()).asDouble().valueSet().ifNotExist().create();
}
break;
}
return res.toString();
}
/**
* 获取所有顶点标签
* @param falg
* @return
* @throws IOException
*/
public static String getAllLabel(String falg) throws IOException{
HugeClient hugeClient = getHugeClient(falg);
GremlinManager gremlin = hugeClient.gremlin();
ResultSet resultSet = gremlin.gremlin("g.V()").execute();
List<Object> list = resultSet.data();
System.out.print(resultSet);
JSONArray jsonarray = JSONArray.fromObject(list);
return jsonarray.toString();
}
}
3. RestTemplateUtil (interface calling tool class)
package net.beidousky.web.app.utils;
import net.beidousky.web.app.component.ReturnErrorJsonHandler;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.web.client.RestTemplate;
import java.util.*;
/**
* 接口工具类
*
* @author jwb
*/
public class RestTemplateUtil {
/**
* 图数据库调用post方法
* @param json
* @param url
* @return
*/
public static String hugeGraphRest(String json, String url, String userName, String password) {
RestTemplate template =new RestTemplate();
//自定义异常处理用于解决调用hugeGraph返回异常结果读取message信息
template.setErrorHandler(new ReturnErrorJsonHandler());
HttpHeaders headers = new HttpHeaders();
MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
headers.setContentType(type);
//添加账号密码验证
headers.add("Authorization", "Basic " + Base64.getUrlEncoder().encodeToString((userName + ":" + password).getBytes()));
headers.add("Accept", MediaType.APPLICATION_JSON.toString());
HttpEntity<String> formEntity = new HttpEntity<String>(json, headers);
String result= template.postForEntity(url,formEntity,String.class).getBody();
return result;
}
/**
* 图数据库调用get方法
* @param
* @param url
* @return
*/
public static String hugeGraphGet(String url, String userName, String password) {
RestTemplate template =new RestTemplate();
//自定义异常处理用于解决调用hugeGraph返回异常结果读取message信息
template.setErrorHandler(new ReturnErrorJsonHandler());
HttpHeaders headers = new HttpHeaders();
MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
headers.setContentType(type);
//添加账号密码验证
headers.add("Authorization", "Basic " + Base64.getUrlEncoder().encodeToString((userName + ":" + password).getBytes()));
headers.add("Accept", MediaType.APPLICATION_JSON.toString());
String result= template.getForEntity(url,String.class,headers).getBody();
return result;
}
}
4. ReturnErrorJsonHandler (custom exception handling is used to solve the problem of calling hugeGraph to return abnormal results and read message information)
package net.beidousky.web.app.component;
import org.apache.commons.lang3.ObjectUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.lang.Nullable;
import org.springframework.web.client.DefaultResponseErrorHandler;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.HttpServerErrorException;
import org.springframework.web.client.UnknownHttpStatusCodeException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* 自定义异常处理用于解决调用hugeGraph返回异常结果读取message信息
*/
public class ReturnErrorJsonHandler extends DefaultResponseErrorHandler {
//调用父类方法就行
public boolean hasError(ClientHttpResponse response) throws IOException {
return super.hasError(response);
}
//重写该方法调用重写的getErrorMessage方法
public void handleError(ClientHttpResponse response) throws IOException {
HttpStatus statusCode = HttpStatus.resolve(response.getRawStatusCode());
if (statusCode == null) {
byte[] body = this.getResponseBody(response);
String message = this.getErrorMessage( body, this.getCharset(response));
throw new UnknownHttpStatusCodeException(message, response.getRawStatusCode(), response.getStatusText(), response.getHeaders(), body, this.getCharset(response));
} else {
this.handleError(response, statusCode);
}
}
//重写该方法，让它返回我们要的格式
private String getErrorMessage(@Nullable byte[] responseBody, @Nullable Charset charset) {
if (ObjectUtils.isEmpty(responseBody)) {
return "[no body]";
} else {
charset = charset == null ? StandardCharsets.UTF_8 : charset;
int maxChars = 200;
if (responseBody.length < maxChars * 2) {
//主要是这里
String message= new String(responseBody, charset);
//Unicode 转换为汉字
return UnicodeToString(message);
} else {
try {
Reader reader = new InputStreamReader(new ByteArrayInputStream(responseBody), charset);
CharBuffer buffer = CharBuffer.allocate(maxChars);
reader.read(buffer);
reader.close();
buffer.flip();
return buffer.toString() + "... (" + responseBody.length + " bytes)";
} catch (IOException var9) {
throw new IllegalStateException(var9);
}
}
}
}
/**
* 将 Unicode 转换为汉字
* */
public String UnicodeToString(String str) {
Pattern pattern = Pattern.compile("(\\\\u(\\p{XDigit}{4}))");
Matcher matcher = pattern.matcher(str);
char ch;
while (matcher.find()) {
ch = (char) Integer.parseInt(matcher.group(2), 16);
str = str.replace(matcher.group(1), ch + "");
}
return str;
}
//重写该方法调用重写的getErrorMessage方法
protected void handleError(ClientHttpResponse response, HttpStatus statusCode) throws IOException {
String statusText = response.getStatusText();
HttpHeaders headers = response.getHeaders();
byte[] body = this.getResponseBody(response);
Charset charset = this.getCharset(response);
String message = this.getErrorMessage(body, charset);
switch(statusCode.series()) {
case CLIENT_ERROR:
throw HttpClientErrorException.create(message, statusCode, statusText, headers, body, charset);
case SERVER_ERROR:
throw HttpServerErrorException.create(message, statusCode, statusText, headers, body, charset);
default:
throw new UnknownHttpStatusCodeException(message, statusCode.value(), statusText, headers, body, charset);
}
}
}
5. hugeGraph.properties (configuration file, due to business needs, multiple graph databases are configured, so there will be multiple configuration graph database connection information in the configuration file, which is read dynamically)
NINTH = {
"ip":"http://ip:端口","hugegraph_graph_name":"图数据库名称","userName":"账号","password":"密码"}
SECOND = {
"ip":"http://ip:端口2","hugegraph_graph_name":"图数据库名称","userName":"账号","password":"密码"}
6. HugegraphTest (test class)
package net.beidousky.web.app.controller;
import com.alibaba.fastjson.JSON;
import net.beidousky.web.app.domain.Result;
import net.beidousky.web.app.entity.hugegraph.Property;
import net.beidousky.web.app.utils.HugeGraphUtils;
import java.io.IOException;
public class HugegraphTest {
/**
* 属性操作--创建属性
* @throws IOException
*/
@org.junit.jupiter.api.Test
public void createPropertyKey() throws IOException{
Property property = new Property();
property.setName("测试7");
property.setData_type("TEXT");
property.setCardinality("SINGLE");
String json = JSON.toJSONString(property);
Result resultSet = HugeGraphUtils.createPropertyKey("NINTH",json);
String jsons = JSON.toJSONString(resultSet);
System.out.print(jsons);
}
}
7. HugeClientVo (graph database connection entity)
package net.beidousky.web.app.entity;
import lombok.Data;
/**
* hugegraph连接实体
*/
@Data
public class HugeClientVo {
//hugegraph连接地址
private String ip;
//hugegraph名称
private String hugegraphGraphName;
//hugegraph用户名
private String userName;
//hugegraph密码
private String password;
}
8. Property (property parameter entity)
package net.beidousky.web.app.entity.hugegraph;
import lombok.Data;
@Data
public class Property {
//属性名称
private String name;
//属性类型只支持–STRING|INT|FLOAT|DATE|BOOLEAN|BLOB
private String data_type;
//属性基数
private String cardinality;
}
Finally, post the code directory
. It is not easy to create. Please help me follow the official account. Thank you.
