Hive-JDBC流程
具体语句代码解释参照此文：MySQL-JDBC详细介绍，和MySQL的jdbc基本上没啥大的区别
二、添加config配置文件和日志配置
- 新建资源包以及config、日志的配置文件
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、初始化资源类
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不能没有
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、执行sql语句类
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连在一起，加一个空格
}
return builder.toString();
}
}
4.1、上面的readSql方法为读取文件中的sql语句，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连在一起，加一个空格
}
return builder.toString();
}
五、结果集类
package cn.kgc.hive.jdbc.hdbc;
public abstract class Result<T> {
private boolean err;
private T data;
//用来统一格式，构造方法私有，统一收口
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) {
};
}
//构造器
private Result(boolean err, T...data) {
this.err = err;
this.data = data.length>0?data[0]:null;
}
public T getData() {
return data;
}
}
六、测试类
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依赖
<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>