java可以通过Apache HttpClient请求接口数据
Apache HttpClient maven jar包引入：
org.apache.httpcomponents
httpcore
4.4.6
org.apache.httpcomponents
httpclient
4.5.2
请求接口方法工具类
package com.test.app.utils;
import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
/**
* @description TODO
* @Author zhaohy
**/
public class HttpUtil {
public static String post(JSONObject json, String url) throws Exception{
CloseableHttpClient httpclient = HttpClientBuilder.create().build();
HttpPost post = new HttpPost(url);
CloseableHttpResponse response = null;
InputStream in = null;
BufferedReader br = null;
String result = "";
try {
StringEntity s = new StringEntity(json.toString(),"utf-8");
s.setContentEncoding("UTF-8");
/*发送json数据需要设置contentType*/
s.setContentType("application/json");
post.setEntity(s);
post.setHeader("Content-Type","application/json;charset=utf-8");
response = httpclient.execute(post);
in = response.getEntity().getContent();
br = new BufferedReader(new InputStreamReader(in, "utf-8"));
StringBuilder strber= new StringBuilder();
String line = null;
while((line = br.readLine())!=null){
strber.append(line+'\n');
}
result = strber.toString();
if(response.getStatusLine().getStatusCode()!=HttpStatus.SC_OK){
if(StringUtils.isBlank(result)) result = "服务器异常";
throw new Exception(result);
}
// System.out.println("返回数据="+result);
} catch (Exception e) {
//System.err.println("调用接口出错：：：：：：：：：：：："+e.getMessage());
throw new Exception(e.getMessage());
} finally {
response.close();
httpclient.close();
br.close();
in.close();
}
return result;
}
public static String get(JSONObject paramsObj, String url, Map headerMap) throws Exception {
CloseableHttpClient httpclient = HttpClientBuilder.create().build();
CloseableHttpResponse response = null;
InputStream in = null;
BufferedReader br = null;
String result = "";
try {
StringBuffer param = new StringBuffer();
int i = 0;
Set> entries = paramsObj.entrySet();
for (Entry entry:entries){
if (i == 0)
param.append("?");
else
param.append("&");
param.append(entry.getKey()).append("=").append(entry.getValue());
i++;
}
url += param;
HttpGet post = new HttpGet(url);
post.setHeader("Content-Type","application/json;charset=utf-8");
Set> headerEntries = headerMap.entrySet();
for (Entry headerEntry:headerEntries){
post.setHeader(headerEntry.getKey(), headerEntry.getValue());
}
response = httpclient.execute(post);
in = response.getEntity().getContent();
br = new BufferedReader(new InputStreamReader(in, "utf-8"));
StringBuilder strber= new StringBuilder();
String line = null;
while((line = br.readLine())!=null){
strber.append(line+'\n');
}
result = strber.toString();
if(response.getStatusLine().getStatusCode()!=HttpStatus.SC_OK){
if(StringUtils.isBlank(result)) result = "服务器异常";
throw new Exception(result);
}
//System.out.println("返回数据="+result);
} catch (Exception e) {
// System.err.println("调用接口出错：：：：：：：：：：：："+e.getMessage());
throw new Exception(e.getMessage());
} finally {
response.close();
httpclient.close();
br.close();
in.close();
}
return result;
}
}
上面的post方法 丢一个JSONObject类型的json参数进去作为请求api的参数，url是api请求地址 返回String类型的json数据。
调用实例：
JSONObject params = new JSONObject();
params.put("area_type","region");
params.put("area_codes",new JSONArray());
params.put("linkage", 1);
String resultJson = HttpUtil.post(params, regionProvinceCityApiUrl);
如此就可以成功返回数据并对返回的json做进一步处理了。
有的时候入库数据字段比较多 实体类如果手动创建会写一大堆的字段，这里介绍一个根据数据库表自动生成实体类的工具类，当然mybatis有自带类似功能的插件，但是这个工具类是通过jdbc连接数据库，理论上不挑框架。
package com.test.app.utils;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* @description 实体类代码生成器
**/
public class ModelCodeGenerator {
//基本数据配置
private String packageOutPath = "com.test.app.model";// 指定实体生成所在包的路径
private String authorName = "zhaohy";// 作者名字
private String tablename = "FDM_INDRS_MONTH_KPI_REPORT_ORI";// 表名
private String modelName = "MonthKpi";// 实体类名
private String[] colnames; // 列名数组
private String[] colTypes; // 列名类型数组
private String version = "V1.0"; // 版本
private int[] colSizes; // 列名大小数组
private boolean f_util = false; // 是否需要导入包java.util.*
private boolean f_sql = false; // 是否需要导入包java.sql.*
private boolean f_lang = false; // 是否需要导入包java.sql.*
private String defaultPath = "/src/main/java/";
// 数据库连接
private static final String URL = "jdbc:oracle:thin:@XXXX:1521:DBNT";
private static final String NAME = "XXXX";
private static final String PASS = "XXXX";
private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";
/*
* 构造函数
*/
public ModelCodeGenerator() {
// 创建连接
Connection con;
// 查要生成实体类的表
String sql = "select * from " + tablename;
PreparedStatement pStemt = null;
try {
try {
Class.forName(DRIVER);
} catch (ClassNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
con = DriverManager.getConnection(URL, NAME, PASS);
pStemt = con.prepareStatement(sql);
ResultSet rs2 = pStemt.executeQuery();
ResultSetMetaData rsmd = pStemt.getMetaData();
int size = rsmd.getColumnCount(); // 统计列
colnames = new String[size];
colTypes = new String[size];
colSizes = new int[size];
for (int i = 0; i < size; i++) {
colnames[i] = UnderlineToHump(rsmd.getColumnName(i + 1).toLowerCase());
colTypes[i] = rsmd.getColumnTypeName(i + 1);
//自动生成包配置
// if (colTypes[i].equalsIgnoreCase("datetime")) {
// f_util = true;
// }
if (colTypes[i].equalsIgnoreCase("image") || colTypes[i].equalsIgnoreCase("text")
|| colTypes[i].equalsIgnoreCase("datetime") || colTypes[i].equalsIgnoreCase("time")
|| colTypes[i].equalsIgnoreCase("date") || colTypes[i].equalsIgnoreCase("datetime2")) {
f_sql = true;
}
// if (colTypes[i].equalsIgnoreCase("int")) {
// f_lang = true;
// }
colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
}
String content = parse(colnames, colTypes, colSizes);
try {
File directory = new File("");
String path = this.getClass().getResource("").getPath();
System.out.println(path);
String outputPath = directory.getAbsolutePath() + this.defaultPath
+ this.packageOutPath.replace(".", "/") + "/" + initcap(modelName) + ".java";
System.out.println("执行完毕，生成路径为："+outputPath);
FileWriter fw = new FileWriter(outputPath);
PrintWriter pw = new PrintWriter(fw);
pw.println(content);
pw.flush();
pw.close();
} catch (IOException e) {
e.printStackTrace();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
}
}
/**
* 功能：生成实体类主体代码
*
* @param colnames
* @param colTypes
* @param colSizes
* @return
*/
private String parse(String[] colnames, String[] colTypes, int[] colSizes) {
StringBuffer sb = new StringBuffer();
// 生成package包路径
sb.append("package " + this.packageOutPath + ";\r\n");
// 判断是否导入工具包
if (f_util) {
sb.append("import java.util.Date;\r\n");
}
if (f_sql) {
sb.append("import java.sql.*;\r\n");
}
if (f_lang) {
sb.append("import java.lang.*;\r\n");
}
sb.append("\r\n");
// 注释部分
sb.append(" /**\r\n");
sb.append(" * @文件名称：" + this.modelName + ".java\r\n");
sb.append(" * @创建时间：" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "\r\n");
sb.append(" * @创 建 人：" + this.authorName + " \r\n");
sb.append(" * @文件描述：" + modelName + " 实体类\r\n");
sb.append(" * @文件版本：" + this.version + " \r\n");
sb.append(" */ \r\n");
// 实体部分
sb.append("\r\n\r\npublic class " + initcap(modelName) + "{\r\n");
processAllAttrs(sb);// 属性
processAllMethod(sb);// get set方法
sb.append("}\r\n");
// System.out.println(sb.toString());
return sb.toString();
}
/**
* 功能：生成所有属性
*
* @param sb
*/
private void processAllAttrs(StringBuffer sb) {
for (int i = 0; i < colnames.length; i++) {
sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + colnames[i] + ";\r\n");
}
}
/**
* 功能：生成所有方法
*
* @param sb
*/
private void processAllMethod(StringBuffer sb) {
for (int i = 0; i < colnames.length; i++) {
sb.append("\tpublic void set" + initcap(colnames[i]) + "(" + sqlType2JavaType(colTypes[i]) + " "
+ colnames[i] + "){\r\n");
sb.append("\tthis." + colnames[i] + "=" + colnames[i] + ";\r\n");
sb.append("\t}\r\n");
sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get" + initcap(colnames[i]) + "(){\r\n");
sb.append("\t\treturn " + colnames[i] + ";\r\n");
sb.append("\t}\r\n");
}
}
/**
* 功能：将输入字符串的首字母改成大写
*
* @param str
* @return
*/
private String initcap(String str) {
char[] ch = str.toCharArray();
if (ch[0] >= 'a' && ch[0] <= 'z') {
ch[0] = (char) (ch[0] - 32);
}
return new String(ch);
}
/**
* 功能：获得列的数据类型
*
* @param sqlType
* @return
*/
private String sqlType2JavaType(String sqlType) {
if (sqlType.equalsIgnoreCase("binary_double")) {
return "double";
} else if (sqlType.equalsIgnoreCase("binary_float")) {
return "float";
} else if (sqlType.equalsIgnoreCase("blob")) {
return "byte[]";
} else if (sqlType.equalsIgnoreCase("blob")) {
return "byte[]";
} else if (sqlType.equalsIgnoreCase("char")
|| sqlType.equalsIgnoreCase("nvarchar2")
|| sqlType.equalsIgnoreCase("varchar2")) {
return "String";
} else if (sqlType.equalsIgnoreCase("date")
|| sqlType.equalsIgnoreCase("timestamp")
|| sqlType.equalsIgnoreCase("timestamp with local time zone")
|| sqlType.equalsIgnoreCase("timestamp with time zone")) {
return "Date";
} else if (sqlType.equalsIgnoreCase("number")) {
return "Double";
}
return "String";
}
/**
* 出口 TODO
*
* @param args
*/
public static void main(String[] args) {
new ModelCodeGenerator();
}
/***
* 下划线命名转为驼峰命名
*
* @param para
* 下划线命名的字符串
*/
public static String UnderlineToHump(String para){
StringBuilder result=new StringBuilder();
String a[]=para.split("_");
for(String s:a){
if (!para.contains("_")) {
result.append(s);
continue;
}
if(result.length()==0){
result.append(s.toLowerCase());
}else{
result.append(s.substring(0, 1).toUpperCase());
result.append(s.substring(1).toLowerCase());
}
}
return result.toString();
}
/***
* 驼峰命名转为下划线命名
*
* @param para
* 驼峰命名的字符串
*/
public static String HumpToUnderline(String para){
StringBuilder sb=new StringBuilder(para);
int temp=0;//定位
if (!para.contains("_")) {
for(int i=0;i在上面配置好基本配置，运行一下main方法就能在相应包下生成数据库中相应表对应的实体类
下面贴一个入库的代码实例：
public void provinceCityTask() {
System.out.println("==================同步省份城市信息数据==================");
JSONObject params = new JSONObject();
params.put("area_type","province");
params.put("area_codes",new JSONArray());
params.put("linkage", 1);
String resultJson = HttpUtil.post(params, regionProvinceCityApiUrl);
// "{\"provinces\":[{\"province_code\":\"20000\",\"province_name\":\"广东省\",\"citys\":[{\"city_code\":\"30000\",\"city_name\":\"广州市\"}]}]}";
if(resultJson != null){
JSONObject resultObj = JSONObject.parseObject(resultJson);
JSONArray jsonArr = resultObj.getJSONArray("provinces");
System.out.println("获取省份城市数据条数："+jsonArr.size());
List> regionCityList = new ArrayList>();
Map regionCityMap = null;
for(int i = 0,length = jsonArr.size(); i < length; i++){
JSONObject jsonObj = jsonArr.getJSONObject(i);
JSONArray citiesArr = jsonObj.getJSONArray("citys");
for(int j = 0; j < citiesArr.size(); j++) {
JSONObject citiesObj = citiesArr.getJSONObject(j);
regionCityMap = new HashMap();
regionCityMap.put("provinceCode",jsonObj.get("province_code"));
regionCityMap.put("provinceName",jsonObj.get("province_name"));
regionCityMap.put("cityCode", citiesObj.get("city_code"));
regionCityMap.put("cityName", citiesObj.get("city_name"));
regionCityList.add(regionCityMap);
}
}
int num = synDataMapper.batchInsertProvinceCityData(regionCityList);
System.out.println("新增省份城市："+num+"条");
}else{
System.out.println("获取省份城市数据返回null!");
System.out.println("params="+JSON.toJSONString(params));
System.out.println("monthKpiUrl="+monthKpiUrl);
}
System.out.println("==================结束同步省份城市数据==================");
}
xml:
begin
delete from DM_PROVINCE_CITY_ORI;
INSERT ALL
into DM_PROVINCE_CITY_ORI
(
province_code,
province_name,
city_code,
city_name,
)
values
(
#{item.provinceCode},
#{item.provinceName},
#{item.cityCode},
#{item.cityName},
)
SELECT 1 FROM DUAL;
end;