Question

这是我在我的项目中读取.properties文件的代码。

public class Configuration {

    private static JSONObject readConfigFile(File filename) throws JSONException {

        JSONObject configProperties = new JSONObject();
        Properties prop = new Properties();
        InputStream input = null;

        try {

            input = new FileInputStream(filename);

            // load a properties file
            prop.load(input);

            // get the property value and print it out


        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            if (input != null) {
                try {
                    input.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return configProperties;

    }

    public static JSONObject loadConfigurationDetails(String configFilePath) throws JSONException {
        JSONObject configurationDetails = new JSONObject();

        File configFile = new File(configFilePath);

        if(configFile.exists()){
            configurationDetails = readConfigFile(configFile);
        }else{
            System.out.println("configuration.properties file not found");
            System.exit(0);
        }

        return configurationDetails;
    }

    public static JSONObject loadConfigurationDetails() throws JSONException {

        String configFilePath = "configuration.properties";

        JSONObject loadConfigurationDetails = loadConfigurationDetails(configFilePath);

        return loadConfigurationDetails;
    }
}

以下是我的项目结构

项目名称
    -src
    -target
    -properties文件
    -pom.xml

您可以查看我的项目结构：link

我的属性文件位于根项目下。我在构建jar文件并运行它时无法读取此文件。我找不到属性文件的文件。

在我的Main方法中，我按如下方式调用我的方法：

JSONObject loadConfigurationDetails = Configuration.loadConfigurationDetails();

修改后的代码和错误

public class Configuration {

  public static JSONObject loadConfigurationDetails() throws JSONException {

    Properties prop = new Properties();
    String filePath = "";
        JSONObject configProperties = new JSONObject();
    try {

      InputStream inputStream = 
        Configuration.class.getClassLoader().getResourceAsStream("configuration.properties");

      prop.load(inputStream);
      configProperties.put("URL",prop.getProperty("URL",""));

    } catch (IOException e) {
        e.printStackTrace();
    }

    return configProperties;

  }

}


Exception in thread "main" java.lang.NullPointerException
    at java.util.Properties$LineReader.readLine(Properties.java:434)
    at java.util.Properties.load0(Properties.java:353)
    at java.util.Properties.load(Properties.java:341)
    at com.demo.main.Configuration.loadConfigurationDetails(Configuration.java:33)
    at com.demo.main.Run.main(Run.java:30)

Answer 1

您需要从类路径中读取它。所以，假设它位于JAR的根目录（它将在src / main / resources / my.props的标准Maven项目布局下）：

input = Configuration.class.getResourceAsStream(filename);

http://docs.oracle.com/javase/6/docs/api/java/lang/ClassLoader.html#getResourceAsStream(java.lang.String)

在jar中找不到属性文件

1 个答案: