1、遇到問題

（1）Maven專案開發階段正常執行，Java程式可以讀取配置檔案

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專案打成jar包後，放到伺服器上執行時，卻報錯，找不到配置檔案。

[[email protected]
 
 ~]# java -jar webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar 
file:/root/webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar!/resources/sharepointApp.xml
Exception 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.<init>(FileInputStream.java:138)
    at java.io.FileInputStream.<init>(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)
[[email protected] ~]#

（3）檢視jar結構，對應配置檔案存在。

[[email protected] ~]# jar tf webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar
。。。
DownloadDemo.class
Main.class
META-INF/maven/cn.hadron/webservice/pom.properties
META-INF/maven/cn.hadron/webservice/pom.xml
resources/a.xml
resources/result.xml
resources/sharepoint.xml
resources/sharepointApp.xml
resources/table.xml
Test.class
META-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/
[[email protected] ~]#

2、問題分析

由上面執行jar包輸出/root/webservice-0.0.1-SNAPSHOT-jar-with-dependencies.jar!/resources/sharepointApp.xml可知，該值是我們通過自定義方法readFile()讀取的檔案路徑，顯然這個值不是一般意義上的URL地址。所以jar包中的類原始碼用File f=new File(專案內地址)的形式，是不可能定位到檔案資源的。

3、解決辦法

jar中資源有其專門的URL形式：jar:<url>!/{entry}
可以通過Class類的getResourceAsStream()方法來獲取資原始檔輸入流方式讀取檔案。

public class FileUtil {
    /**
     * 讀取配置檔案
     * @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");

    }
}