java - 在java程序中加载一个csv文件

Question

当我尝试运行此基准测试时 java8-lambda-benchmark .

使用命令:

java -cp build/jar/LambdaMicrobench.jar lambdademo.LambdaAvgExtraParallel 50000

我收到以下错误:

lambdademo/load_employees.csv: Not found in jar
java.lang.NullPointerException
at lambdademo.EmployeeFile.loadEmployeeList(Unknown Source)
at lambdademo.LambdaAvgExtraParallel.main(Unknown Source)
Exception in thread "main" java.lang.NullPointerException
at lambdademo.EmployeeFile.loadEmployeeList(Unknown Source)
at lambdademo.LambdaAvgExtraParallel.main(Unknown Source

文件 EmployeFile.java 如下:

public class EmployeeFile {

private static final String EMPLOYEE_FILE = "lambdademo/load_employees.csv";

public LinkedList<EmployeeRec> loadEmployeeList() {
    LinkedList<EmployeeRec> employeeList = new LinkedList<>();
    BufferedReader br = null;
    try {
         URL fileURL = getClass().getClassLoader().getResource(EMPLOYEE_FILE);
          if (fileURL == null) {
                   System.out.println("resource is null");
             }
          InputStream in = fileURL.openStream();
          br = new BufferedReader(new InputStreamReader(in));             
               } catch (Exception e) {
        System.out.println(EMPLOYEE_FILE + ": Not found in jar");
        e.printStackTrace();
    }

    try {
        String line;
        while ((line = br.readLine()) != null) {    
            String[] rec = null;
            rec = line.split(",");
            employeeList.add(new EmployeeRec(rec[0], rec[1], rec[2],
                    rec[3], rec[4], rec[5]));
        }
    } catch (IOException e) {
        System.out.println("Error reading " + EMPLOYEE_FILE);
        e.printStackTrace();
    }
    return employeeList;
}

现在我打印 fileURL 的值，我得到空值。csv 文件与项目源位于同一文件夹中。

Answer 1

当我使用 jar -xvf build/jar/LambdaMicrobench.jar我得到这个输出

 created: META-INF/
inflated: META-INF/MANIFEST.MF
 created: lambdademo/
inflated: lambdademo/Constants.class
inflated: lambdademo/EmployeeFile.class
inflated: lambdademo/EmployeeRec.class
inflated: lambdademo/LambdaAvgExtraParallel.class
inflated: lambdademo/LambdaAvgExtraSerial.class
inflated: lambdademo/LambdaAvgParallel.class
inflated: lambdademo/LambdaAvgSerial.class
inflated: lambdademo/OldSchoolAvg.class
inflated: lambdademo/OldSchoolAvgExtra.class
inflated: load_employees.csv

这些是正确的，因为项目文件结构是:

--LambdaMicrobench
----load_employees.csv
----lambdademo
------*.class

解决方案是更改该字段，load_employees.csv 而不是 lambdademo/load_employees.csv

private static final String EMPLOYEE_FILE = "load_employees.csv";