springboot项目hadoop3.2.1配置公网访问+封装工具类

如果通过公网的方式访问namenode，也就是公网存储文件，需要
服务器 hdfs-site.xml需要添加

<property>
    <name>dfs.client.use.datanode.hostname</name>
    <value>true</value>
    <description>only cofig in clients</description>
</property>

客户端测试代码（注意如果是本地需要连接线上那么本地也需要下载hadoop并配置hadoop的环境变量）

Configuration conf = new Configuration();
conf.set("dfs.client.use.datanode.hostname", "true");
FileSystem fs = FileSystem.get(new URI("hdfs://106.53.25.61:9000"), conf);
fs.copyFromLocalFile(new Path("D:/aaa.txt"), new Path("/user"));
//fs.copyToLocalFile(new Path("/user/NOTICE.txt"),new Path("/user/aa.txt"));
//InputStream in = fs.open(new Path("/user/NOTICE.txt"));
//FileOutputStream out = new FileOutputStream(new File("D:/A.txt"));
//IOUtils.copyBytes(in, out, 2048, true);
fs.close();
System.out.println("上传完毕");

工具类代码：

package com.tools.common.helper;

import lombok.extern.slf4j.Slf4j;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.util.ObjectUtils;

import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URI;

@Component
@Slf4j
public class HdfsHelper {
    private static String hdfsUrl;
    public static String rootDir;
    private static Configuration configuration;

    private static void buildConfig() {
        if (ObjectUtils.isEmpty(configuration)) {
            configuration = new Configuration();
            configuration.set("dfs.client.use.datanode.hostname", "true");
        }
    }

    /**
     * 创建目录
     *
     * @param path 需要创建的目录 例如 /user/aa 可以建立多级
     * @return
     */
    public static boolean mkdir(String path) throws Exception {
        buildConfig();
        FileSystem fileSystem = FileSystem.get(new URI(hdfsUrl), configuration);
        fileSystem.mkdirs(new Path(String.format("%s%s", rootDir, path)));
        fileSystem.close();
        return true;
    }

    /**
     * 上传文件
     *
     * @param sourcePath 本地文件路径 例如 D:/test.txt
     * @param targetPath hdfs存放路径 例如 /test/test.txt
     * @param delFile    是否删除本地文件
     * @return
     */
    public static boolean upload(String sourcePath, String targetPath, boolean delFile) throws Exception {
        buildConfig();
        FileSystem fileSystem = FileSystem.get(new URI(hdfsUrl), configuration);
        fileSystem.copyFromLocalFile(delFile, new Path(sourcePath), new Path(String.format("%s%s", rootDir, targetPath)));
        fileSystem.close();
        return true;
    }

    /**
     * 上传文件
     *
     * @param sourcePath 本地文件路径 例如 D:/test.txt
     * @param targetPath hdfs存放路径 例如 /test/test.txt
     * @return
     */
    public static boolean upload(String sourcePath, String targetPath) throws Exception {
        return upload(sourcePath, targetPath, false);
    }

    /**
     * 下载文件
     *
     * @param sourcePath hdfs文件路径 例如 /test/test.txt
     * @param targetPath 本地存放路径 例如 D:/test.txt
     * @param delFile
     * @return
     * @throws Exception
     */
    public static boolean download(String sourcePath, String targetPath, boolean delFile) throws IOException {
        buildConfig();
        FileSystem fileSystem = null;
        FSDataInputStream fsdis = null;
        FileOutputStream fos = null;
        try {
            fileSystem = FileSystem.get(new URI(hdfsUrl), configuration);
            fsdis = fileSystem.open(new Path(String.format("%s%s", rootDir, sourcePath)));
            fos = new FileOutputStream(targetPath);
            byte[] buffer = new byte[2048];
            int index = 0;
            while ((index = fsdis.read(buffer)) != -1) {
                fos.write(buffer, 0, index);
            }
            fos.flush();
            if (delFile) {
                delete(sourcePath);
            }
        } catch (Exception e) {
            log.error("HdfsHelper download error:", e);
            return false;
        } finally {
            if (!ObjectUtils.isEmpty(fos)) {
                fos.close();
            }
            if (!ObjectUtils.isEmpty(fsdis)) {
                fsdis.close();
            }
            if (!ObjectUtils.isEmpty(fileSystem)) {
                fileSystem.close();
            }
        }
        return true;
    }

    /**
     * 获取文件字节数组
     *
     * @param sourcePath hdfs文件路径 例如 /test/test.txt
     * @return
     * @throws Exception
     */
    public static byte[] getFileBytes(String sourcePath) throws IOException {
        buildConfig();
        FileSystem fileSystem = null;
        FSDataInputStream fsdis = null;
        ByteArrayOutputStream bos = null;
        byte[] bytes;
        try {
            fileSystem = FileSystem.get(new URI(hdfsUrl), configuration);
            fsdis = fileSystem.open(new Path(String.format("%s%s", rootDir, sourcePath)));
            bos = new ByteArrayOutputStream();
            byte[] buffer = new byte[2048];
            int index = 0;
            while ((index = fsdis.read(buffer)) != -1) {
                bos.write(buffer, 0, index);
            }
            bytes = bos.toByteArray();
        } catch (Exception e) {
            log.error("HdfsHelper download error:", e);
            return null;
        } finally {
            if (!ObjectUtils.isEmpty(bos)) {
                bos.close();
            }
            if (!ObjectUtils.isEmpty(fsdis)) {
                fsdis.close();
            }
            if (!ObjectUtils.isEmpty(fileSystem)) {
                fileSystem.close();
            }
        }
        return bytes;
    }


    /**
     * 下载文件
     *
     * @param sourcePath hdfs文件路径 例如 /test/test.txt
     * @param targetPath 本地存放路径 例如 D:/test.txt
     * @return
     * @throws Exception
     */
    public static boolean download(String sourcePath, String targetPath) throws Exception {
        return download(sourcePath, targetPath, false);
    }

    /**
     * 判断文件或者目录是否存在
     *
     * @param path
     * @return
     */
    public static boolean isExist(String path) throws Exception {
        buildConfig();
        FileSystem fileSystem = FileSystem.get(new URI(hdfsUrl), configuration);
        return fileSystem.exists(new Path(String.format("%s%s", rootDir, path)));
    }

    /**
     * 删除文件或者目录
     *
     * @param path 目录路径 或者 文件路径
     * @return
     * @throws Exception
     */
    public static boolean delete(String path) throws Exception {
        buildConfig();
        FileSystem fileSystem = FileSystem.get(new URI(hdfsUrl), configuration);
        fileSystem.deleteOnExit(new Path(String.format("%s%s", rootDir, path)));
        fileSystem.close();
        return true;
    }

    @Value("${hdfs.url}")
    public void setHdfsUrl(String hdfsUrl) {
        HdfsHelper.hdfsUrl = hdfsUrl;
    }

    @Value("${hdfs.root-dir}")
    public void setRootDir(String rootDir) {
        HdfsHelper.rootDir = rootDir;
    }
}

项目yml配置

hdfs:
  url: hdfs://你的ip:9000
  root-dir: /test

碰到的问题

win10的3.2.1存在无法格式化namenode的问题，切换到3.1.2版本后此问题解决。