Heck's Blog

Spring中autowire属性
default-autowire="x"
x有5个选择：byName,byType,constructor和autodetect,no

一、spring 自动装配 default-autowire="byName"

Service.java

public class Service
{
    Source source;

    public void setSource(Source source)
    {
        this.source = source;
    }
}

首先我们看下什么是属性编辑器，到底它有什么作用呢？
* 自定义属性编辑器，spring配置文件中的字符串转换成相应的对象进行注入
spring已经有内置的属性编辑器，我们可以根据需求自己定义属性编辑器

* 如何定义属性编辑器？
  * 继承PropertyEditorSupport类，覆写setAsText()方法（注意要将处理完成的对象通过PropertyEditorSupport的setValue设置回去）
*向IoC容器中注册自定义的属性编辑器(两种方式：1 在配置文件中注册 2 在程序中注册)
接下来我们就看看一个关于日期的属性编辑器的部署过程：
首先定义一个测试类：

比如：
有一个类里面有一个Date属性
package tk.hecks.property;

import java.util.Date;

public class User {
  private String username;
  private Date birthday;
  public String getUsername() {
    return username;
  }
  public void setUsername(String username) {
    this.username = username;
  }
  public Date getBirthday() {
    return birthday;
  }
  public void setBirthday(Date birthday) {
    this.birthday = birthday;
  }

}

Failed to convert property value of type [$Proxy13
Failed to convert property value of type [$Proxy13] to required type

PropertyAccessException 1: org.springframework.beans.TypeMismatchException: Failed to convert property value of type [$Proxy13] to required type [tk.hecks.dao.AuthorDaoImp] for property 'authorDaoImp'; nested exception is java.lang.IllegalArgumentException: Cannot convert value of type [$Proxy13] to required type [tk.hecks.dao.AuthorDaoImp] for property 'authorDaoImp': no matching editors or conversion strategy found  
Caused by:  
org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessException details (1) are:  
PropertyAccessException 1:  
org.springframework.beans.TypeMismatchException: Failed to convert property value of type [$Proxy13] to required type [tk.hecks.dao.AuthorDaoImp] for property 'authorDaoImp'; nested exception is java.lang.IllegalArgumentException: Cannot convert value of type [$Proxy13] to required type [tk.hecks.dao.AuthorDaoImp] for property 'authorDaoImp': no matching editors or conversion strategy found  
Caused by:  
java.lang.IllegalArgumentException: Cannot convert value of type [$Proxy13] to required type [tk.hecks.dao.AuthorDaoImp] for property 'authorDaoImp': no matching editors or conversion strategy found  
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:231)  
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:138)  
at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:815)