对WebHDFS的弹簧支持

Question

有什么Spring支持的楔子吗？我在google上没有找到任何有用的链接。

我想通过webhdfs通过普通身份验证和kerberos身份验证连接到hadoop。这个在春天支持吗？

任何有用的链接都是有帮助的。

谢谢

Answer 1

是的，Spring数据支持这一点。根据本文档，可以配置任何支持的Hadoop文件系统：

http://docs.spring.io/spring-hadoop/docs/current/reference/html/fs.html

SHDP不强制使用任何特定的协议--事实上，正如本节所述，可以使用任何FileSystem实现，甚至允许使用HDFS以外的其他实现。

有关演示将WebHDFS FileSystem实例自动连接到命令行应用程序的代码示例，请参阅下面的内容。要运行此操作，将文件路径作为命令行参数传递，它将通过调用FileSystem.listStatus列出该路径上的每个文件。

代码示例被配置为通过“简单”身份验证连接到不安全的WebHDFS实例。要连接到使用Kerberos保护的WebHDFS实例，您需要在<hdp:configuration id="hadoopConfiguration" /> bean中设置相关的配置属性。Hadoop安全配置是一个非常大的主题。与其重复这些信息，我只会指向Apache中的文档：

http://hadoop.apache.org/docs/r2.4.1/hadoop-project-dist/hadoop-common/SecureMode.html

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>test-spring-hadoop</groupId>
    <artifactId>test-webhdfs</artifactId>
    <packaging>jar</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>Test Spring Hadoop with WebHDFS</name>
    <description>Test Spring Hadoop with WebHDFS</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.1.0.RELEASE</version>
    </parent>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <url>http://repo.spring.io/libs-release</url>
        </repository>
    </repositories>

    <properties>
        <start-class>testwebhdfs.Main</start-class>
        <java.version>1.6</java.version>
        <hadoop.version>2.4.1</hadoop.version>
    </properties>

    <build>
        <plugins>            
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-hadoop</artifactId>
            <version>2.0.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-hdfs</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
    </dependencies>
</project>

src/main/resources/hadoop-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:hdp="http://www.springframework.org/schema/hadoop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                   http://www.springframework.org/schema/hadoop http://www.springframework.org/schema/hadoop/spring-hadoop.xsd">

    <hdp:configuration id="hadoopConfiguration" />
    <hdp:file-system uri="webhdfs://localhost:50070" />
</beans>

src/main/java/testwebhdfs/Main.java

package testwebhdfs;

import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportResource;

@Configuration
@ImportResource("hadoop-context.xml")
public class Main implements CommandLineRunner {

    @Autowired
    private FileSystem fs;

    @Override
    public void run(String... strings) throws Exception {
        Path[] paths = new Path[strings.length];
        for (int i = 0; i < strings.length; ++i) {
            paths[i] = new Path(strings[i]);
        }
        for (FileStatus stat: fs.listStatus(paths)) {
            System.out.println(stat.getPath());
        }
    }

    public static void main(String[] args) {
        SpringApplication.run(Main.class, args);
    }
}