java 读取hdfs上的文件内容

用java读取hdfs的文件

直接撸代码:

package com.nature.base.util;

import com.nature.component.process.vo.DebugDataResponse;
import org.apache.commons.lang3.StringUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.slf4j.Logger;

import java.io.*;
import java.net.URI;
import java.util.*;

/**
 * 操作hdfs文件的工具类
 */

public class HdfsUtils {

    private static Logger logger = LoggerUtil.getLogger();

    /**
     * 读取hdfs指定路径的内容
     */
    public static String gethdfsData(String hdfsPath){
        String result = "";
        if(com.nature.third.utils.StringUtils.isNotEmpty(hdfsPath)){
            Path path = new Path(hdfsPath);
            Configuration configuration = new Configuration();
            FSDataInputStream fsDataInputStream = null;
            FileSystem fileSystem = null;
            BufferedReader br = null;
            // 定义一个字符串用来存储文件内容
            try {
                fileSystem = path.getFileSystem(configuration);
                fsDataInputStream = fileSystem.open(path);
                br = new BufferedReader(new InputStreamReader(fsDataInputStream));
                String str2;
                while ((str2 = br.readLine()) != null) {
                    // 遍历抓取到的每一行并将其存储到result里面
                    result += str2 + "\n";
                }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if(br!=null){
                    try {
                        br.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if(fsDataInputStream!=null){
                    try {
                        fsDataInputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if(fileSystem!=null){
                    try {
                        fileSystem.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            logger.debug("文件内容:" + result);
        }
        return result;
    }

}

核心方法:

Path path = new Path("hdfs://192.168.1.111:9000/test/1234log");
Configuration configuration = new Configuration();
FileSystem fileSystem = path.getFileSystem(configuration);
FSDataInputStream fsDataInputStream = fileSystem.open(path);

注意我加的那些编码格式,可以防止中文乱码!!

这种方式即可以读取hdfs上面的文件也可以读取本地文件

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