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1、遇到问题

（1）Maven项目开发阶段正常运行，Java程序可以读取配置文件

public class Main {    public static void main(String[] args) throws Exception {        Main.readFile("resources/sharepointApp.xml");    }    public static byte[] readFile(String fileName) throws Exception {        String path = SharepointApp.class.getClassLoader().getResource(fileName).getPath();        System.out.println(path);        File file = new File(path);        byte[] buf = new byte[(int) file.length()];        InputStream input=new FileInputStream(fileName);        input.read(buf);        input.close();        return buf;    }}

（2）但是，Maven项目打成jar包后，放到服务器上运行时，却报错，找不到配置文件。

[root@SearchEngine-TEST ~]# java -jar webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar file:/root/webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar!/resources/sharepointApp.xmlException in thread "main" java.io.FileNotFoundException: file:/root/webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar!/resources/sharepointApp.xml (No such file or directory)    at java.io.FileInputStream.open0(Native Method)    at java.io.FileInputStream.open(FileInputStream.java:195)    at java.io.FileInputStream.
   
    (FileInputStream.java:138)    at java.io.FileInputStream.
    
     (FileInputStream.java:93)    at com.cntaiping.tpa.webservice.SharepointApp.readFile(SharepointApp.java:53)    at com.cntaiping.tpa.webservice.SharepointApp.sendSms(SharepointApp.java:30)    at Main.main(Main.java:22)[root@SearchEngine-TEST ~]#
    
   

（3）查看jar结构，对应配置文件存在。

[root@SearchEngine-TEST ~]# jar tf webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar。。。DownloadDemo.classMain.classMETA-INF/maven/cn.hadron/webservice/pom.propertiesMETA-INF/maven/cn.hadron/webservice/pom.xmlresources/a.xmlresources/result.xmlresources/sharepoint.xmlresources/sharepointApp.xmlresources/table.xmlTest.classMETA-INF/maven/commons-io/META-INF/maven/commons-codec/META-INF/maven/commons-codec/commons-codec/META-INF/maven/commons-io/commons-io/META-INF/maven/commons-logging/META-INF/maven/com.github.virtuald/META-INF/maven/com.github.virtuald/curvesapi/META-INF/maven/commons-logging/commons-logging/[root@SearchEngine-TEST ~]#

2、问题分析

由上面运行jar包输出/root/webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar!/resources/sharepointApp.xml可知，该值是我们通过自定义方法readFile()读取的文件路径，显然这个值不是一般意义上的URL地址。所以jar包中的类源代码用File f=new File(项目内地址)的形式，是不可能定位到文件资源的。

3、解决办法

jar中资源有其专门的URL形式：jar:<url>!/{entry}

public class FileUtil {
       /**     * 读取配置文件     * @return     */    public static byte[] readConfigFile(String cfgFile) {        try {            InputStream in=FileUtil.class.getClassLoader().getResource(cfgFile).openStream();            BufferedReader br=new BufferedReader(new InputStreamReader(in));            StringBuilder sb=new StringBuilder();                    String line="";            while((line=br.readLine())!=null) {                sb.append(line);            }            return sb.toString().getBytes();        } catch (IOException e) {            e.printStackTrace();            return null;        }    }    //省略其他的方法    //主方法    public static void main(String[] args) throws IOException {         byte[] buf = FileUtil.readConfigFile("resources/sharepointApp.xml");    }}

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