Spring Data Binding

一） BeanWrapper
BeanWrapper这个类一般不会被Spring的使用者直接调用，而是使用DataBinder和BeanFactory这两个类是间接被调用的。但是知道BeanWrapper的使用方式对于理解Spring的数据绑定机制还是十分用益的。下面我们就来看个BeanWrapper被直接调用的例子：

//首先是两个对象类Company Employee
public class Company {
private String name;
private Employee managingDirector;
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public Employee getManagingDirector() {
return this.managingDirector;
}
public void setManagingDirector(Employee managingDirector) {
this.managingDirector = managingDirector;
}
}

public class Employee {
private String name;
private float salary;
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public float getSalary() {
return salary;
}
public void setSalary(float salary) {
this.salary = salary;
}
}

BeanWrapper company = BeanWrapperImpl(new Company());
// setting the company name..
company.setPropertyValue("name", 
"Some Company Inc.");
// ... can also be done like this:
PropertyValue value = new PropertyValue("name",
"Some Company Inc.");
company.setPropertyValue(value);
// ok, let's create the director and tie it to the company:
BeanWrapper jim = BeanWrapperImpl(new Employee());
jim.setPropertyValue("name", 
"Jim Stravinsky");
company.setPropertyValue("managingDirector", jim.getWrappedInstance());
// retrieving the salary of the managingDirector through the company
Float salary = (Float) company.getPropertyValue("managingDirector.salary");