org.springframework.beans.NotWritablePropertyException：无效的属性

Question

您好，我是 Spring 新手，目前我正在使用 Maven 运行我的应用程序

但是当我运行我的项目时，我遇到了如下异常

bean 类 [com.ensis.spring.MovieLister] 的“年份”：bean 属性“年份”不可写或设置方法无效。 setter 的参数类型是否与 getter 的返回类型匹配？

主要：

public class Main {

    public static void main(String[] args){

        ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext.xml");
        MovieLister movieLister = (MovieLister)ctx.getBean("lister");
        movieLister.printMoviesByYear();
    }
}

电影：

private int year;
    private String name;

    public Movie(int year, String name) {
        super();
        this.year = year;
        this.name = name;
    }

    public int getYear() {
        return year;
    }
    public void setYear(int year) {
        this.year = year;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

电影查找器：

public class MovieFinder {

    private static List<Movie>moviesList;

    static{

        moviesList.add(new Movie(1990, "A"));
        moviesList.add(new Movie(1991, "B"));
        moviesList.add(new Movie(1992, "C"));
        moviesList.add(new Movie(1993, "D"));
        moviesList.add(new Movie(1994, "E"));
        moviesList.add(new Movie(1995, "F"));
    }

    public List<Movie>findMoviesByYear(int year){

        List<Movie>findMovies=new ArrayList<Movie>();

        for(Movie movie:moviesList){
            if(year==movie.getYear()){
                findMovies.add(movie);          
                }
        }

        return findMovies;
    }

}

电影列表：

public class MovieLister {

    private int year;
    private MovieFinder movieFinder;


    public void printMoviesByYear(){

        List<Movie>found = movieFinder.findMoviesByYear(year);
        for(Movie movie:found){
            System.out.println("So movies are======>"+movie.getName());
        }
    }
}

applicationContext.xml

<?xml version = "1.0" encoding = "UTF-8"?>

<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

   <bean id="lister" class ="com.ensis.spring.MovieLister" autowire="byType">
   <property name="year" value="1991"/>
   </bean>
   <bean id="finder" class="com.ensis.spring.MovieFinder"/>
   </beans>

Answer 1

向 MovieLister 添加一个 setter：

public void setYear(final int year) {
  this.year = year;
}

这是必需的，因为成员变量 year 是私有的。

旁注： 如果 MovieLister 实例需要一年或任何其他成员变量，我强烈建议创建一个设置这些变量的构造函数。