使用BeanIO將CSV文件寫入CSV文件

Question

我正嘗試使用BeanIO框架將數據列表寫入CSV文件。我能夠將單個對象寫入CSV，但無法寫入數據列表。

我曾嘗試下面的代碼：

package com.beanio.example; 

import java.util.Date; 

public class Employee { 
    String firstName; 
    String lastName; 
    String title; 
    int salary; 
    Date hireDate; 

    // setters and getters follow ... 
} 

<beanio xmlns="http://www.beanio.org/2012/03" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://www.beanio.org/2012/03 http://www.beanio.org/2012/03/mapping.xsd"> 

    <stream name="employeeFile" format="csv"> 
    <record name="header" class="com.beanio.example.GroupH" order="1" occurs="1"> 
     <field name="h1" default="Header1" ignore="true" /> 
     <field name="h2" default="Header2" ignore="true" /> 
     <field name="h3" default="Header2" ignore="true" /> 
    </record> 
    <record name="employee" class="com.beanio.example.Employee" order="2"> 
     <field name="firstName" /> 
     <field name="lastName" /> 
     <field name="title" /> 
     <field name="salary" /> 
     <field name="hireDate" format="MMddyyyy" /> 
    </record> 
    </stream> 
</beanio> 

public class Main { 
    public static void main(String[] args) throws Exception { 
     // create a StreamFactory 
     StreamFactory factory = StreamFactory.newInstance(); 
     // load the mapping file 
     factory.loadResource("mapping.xml"); 

     List<Employee> employees = new ArrayList<Employee>(); 

     Employee employee = new Employee(); 
     employee.setFirstName("Jennifer"); 
     employee.setLastName("Jones"); 
     employee.setTitle("Marketing"); 
     employee.setSalary(60000); 
     employee.setHireDate(new Date()); 

     Employee employee1 = new Employee(); 
     employee1.setFirstName("JACk"); 
     employee1.setLastName("Jones"); 
     employee1.setTitle("Tele"); 
     employee1.setSalary(60000); 
     employee1.setHireDate(new Date()); 

     employees.add(employee); 
     employees.add(employee1); 

     // use a StreamFactory to create a BeanWriter 
     BeanWriter out = factory.createWriter("employeeFile", new File("employee.csv")); 
     // write an Employee object directly to the BeanWriter 
     out.write(employees); 
     out.flush(); 
     out.close(); 
    } 
} 

我期待在CSV結果按照以下格式：

FirstName,LastName,Title,Salary,HireDate 

例如：

Jennifer,Jones,Marketing,60000,24-12-2016 

JACK,Jones,TELE,60000,24-12-2016 

有人可以幫我嗎？

Answer 1

使用BeanIO，您只能將文件寫入平面文件中作爲單個對象。

儘管您可以使用Spring批量集成與BeanIO來實現它。

http://beanio.org/2.1/docs/reference/index.html#SpringItemReaderWriter

Answer 2

你只需要做到這一點：

for(Employee e: employees){ 
    out.write(e); 
} 

這是全碼：

public class Main { 
    public static void main(String[] args) throws Exception { 
     // create a StreamFactory 
     StreamFactory factory = StreamFactory.newInstance(); 
     // load the mapping file 
     factory.loadResource("mapping.xml"); 

     List<Employee> employees = new ArrayList<Employee>(); 

     Employee employee = new Employee(); 
     employee.setFirstName("Jennifer"); 
     employee.setLastName("Jones"); 
     employee.setTitle("Marketing"); 
     employee.setSalary(60000); 
     employee.setHireDate(new Date()); 

     Employee employee1 = new Employee(); 
     employee1.setFirstName("JACk"); 
     employee1.setLastName("Jones"); 
     employee1.setTitle("Tele"); 
     employee1.setSalary(60000); 
     employee1.setHireDate(new Date()); 

     employees.add(employee); 
     employees.add(employee1); 

     // use a StreamFactory to create a BeanWriter 
     BeanWriter out = factory.createWriter("employeeFile", new File("employee.csv")); 
     // write an Employee object directly to the BeanWriter 
     for(Employee e: employees){ 
      out.write(e); 
     } 
     out.flush(); 
     out.close(); 
    } 
}