Hive-JDBC流程

具體語句代碼解釋參照此文：MySQL-JDBC詳細介紹，和MySQL的jdbc基本上沒啥大的區別

二、添加config配置文件和日誌配置

• 新建資源包以及config、日誌的配置文件
  
  

driver=org.apache.hive.jdbc.HiveDriver
url=jdbc:hive2://192.168.221.140:10000/default
username=root

log4j.rootLogger=INFO, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n
log4j.appender.logfile=org.apache.log4j.FileAppender
log4j.appender.logfile.File=target/hadoop.log
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%d %p [%c] - %m%n

三、初始化資源類

package cn.kgc.hive.jdbc.hdbc;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class BaseConfig {
   
   
    class Config{
   
   
        private String driver;
        private String url;
        private String username;
        private String password;
    }
    private Config config;

    private boolean valid(String url){
   
   
        Pattern p = Pattern.compile("jdbc:\\w+://((\\d{1,3}\\.){3}\\d{1,3}|\\w+):\\d{1,5}/\\w+");//把字符串
        Matcher m = p.matcher(url);
        return m.matches();
    }

    private void init() throws Exception {
   
   
        String path = Thread.currentThread().getContextClassLoader().getResource("datasource.properties").getPath();
        Properties pro = new Properties();
        pro.load(new FileReader(path));
        String url = pro.getProperty("url");//url不能沒有
        if (null==url||!valid(url)){
   
   
            throw new Exception("invalid url exception");
        }
        config = new Config();
        config.url = url;
        config.driver = pro.getProperty("driver","com.mysql.jdbc.Driver");
        config.username = pro.getProperty("username","root");
        config.password= pro.getProperty("password","");
    }

    {
   
   
        try {
   
   
            init();
            Class.forName(config.driver);
        } catch (Exception e) {
   
   
            e.printStackTrace();
        }
    }

    Connection getCon() throws SQLException {
   
   
        return DriverManager.getConnection(config.url,config.username,config.password);
    }

    void close(AutoCloseable...closeables){
   
   
        for (AutoCloseable closeable : closeables) {
   
   
            if (null!=closeable){
   
   
                try {
   
   
                    closeable.close();
                } catch (Exception e) {
   
   
                    e.printStackTrace();
                }
            }
        }
    }
}

四、執行sql語句類

package cn.kgc.hive.jdbc.hdbc;


import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class BaseDao extends BaseConfig {
   
   
    private PreparedStatement getPst(Connection con,String sql,Object...params) throws SQLException {
   
   
        PreparedStatement pst = con.prepareStatement(sql);
        if (params.length>0){
   
   
            for (int i = 0; i < params.length; i++) {
   
   
                pst.setObject(i+1,params[i]);
            }
        }
        return pst;
    }

    public Result exeNonQuery(String sql,Object...params){
   
   
        Connection con =null;
        PreparedStatement pst =null;
        try {
   
   
            con = getCon();
            pst = getPst(con,sql,params);
            pst.execute();
            return Result.succeed();

        } catch (SQLException e) {
   
   
            return Result.fail();
        }finally {
   
   
            close(pst,con);
        }
    }

    public Result exeQuery(String sql,Object...params){
   
   
        Connection con =null;
        PreparedStatement pst = null;
        ResultSet rst = null;
        try {
   
   
            con=getCon();
            pst = getPst(con,sql,params);
            rst = pst.executeQuery();
            List<List<String>> table = null;
            if (null!=rst&&rst.next()){
   
   
                table = new ArrayList<>();
                final int COL = rst.getMetaData().getColumnCount();
                do{
   
   
                    List<String> row = new ArrayList<>(COL);
                    for (int i = 1; i < COL; i++) {
   
   
                        row.add(rst.getObject(i).toString());
                    }
                    table.add(row);
                }while (rst.next());
            }
            return Result.succeed(table);
        } catch (SQLException e) {
   
   
            return Result.fail();
        }finally {
   
   
            close(rst,pst,con);
        }
    }

    public String readSql(String...paths) throws Exception {
   
   
        String path = paths.length==0 ? "sql/sql.sql" : paths[0];
        StringBuilder builder = new StringBuilder();
        BufferedReader reader = new BufferedReader(new FileReader(path));
        String line =null;
        while (null != (line=reader.readLine())){
   
   
            builder.append(line.trim()+" ");//防止第一行和第二行連在一起，加一個空格
        }
        return builder.toString();
    }
}

4.1、上面的readSql方法爲讀取文件中的sql語句，看上去更清晰

    public String readSql(String...paths) throws Exception {
   
   
        String path = paths.length==0 ? "sql/sql.sql" : paths[0];
        StringBuilder builder = new StringBuilder();
        BufferedReader reader = new BufferedReader(new FileReader(path));
        String line =null;
        while (null != (line=reader.readLine())){
   
   
            builder.append(line.trim()+" ");//防止第一行和第二行連在一起，加一個空格
        }
        return builder.toString();
    }

五、結果集類

package cn.kgc.hive.jdbc.hdbc;

public abstract class Result<T> {
   
   
    private  boolean err;
    private  T data;
    //用來統一格式，構造方法私有，統一收口
    public static Result fail(){
   
   
        return new Result(true) {
   
   };
    }
    //加方法集泛型
    public static <T> Result succeed(T...t){
   
   
        return new Result(false,t) {
   
   };
    }
    //構造器
    private Result(boolean err, T...data) {
   
   
        this.err = err;
        this.data = data.length>0?data[0]:null;
    }

    public T getData() {
   
   
        return data;
    }
}

六、測試類

public class Test {
   
   
    public static void main(String[] args) throws Exception {
   
   
        BaseDao dao = new BaseDao();
        Result<List<List<String>>> tables = dao.exeQuery(dao.readSql());
        tables.getData().forEach(row->{
   
   
            row.forEach(item->{
   
   
                System.out.print(item+"\t");
            });
            System.out.println();
        });

    }
}

一、引入pom依賴

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.apache.hive</groupId>
      <artifactId>hive-jdbc</artifactId>
      <version>${
   
   hive.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-auth</artifactId>
      <version>${
   
   hadoop.version}</version>
      <exclusions>
        <exclusion>
          <artifactId>jdk.tools</artifactId>
          <groupId>jdk.tools</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-common</artifactId>
      <version>${
   
   hadoop.version}</version>
      <exclusions>
        <exclusion>
          <artifactId>jdk.tools</artifactId>
          <groupId>jdk.tools</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-hdfs</artifactId>
      <version>${
   
   hadoop.version}</version>
      <exclusions>
        <exclusion>
          <artifactId>jdk.tools</artifactId>
          <groupId>jdk.tools</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-client</artifactId>
      <version>${
   
   hadoop.version}</version>
      <exclusions>
        <exclusion>
          <artifactId>jdk.tools</artifactId>
          <groupId>jdk.tools</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-mapreduce-client-core</artifactId>
      <version>${
   
   hadoop.version}</version>
    </dependency>
  </dependencies>