How do JSP pages find the correct setters for parameters

Say I have the following JSP page:

<jsp:useBean id="bean" scope="page" class="com.test.jsp.beans.TestBean"/>
<jsp:setProperty name="bean" property="*"/>
...
<input type="text" name="test" value="test value"/>
...

and the bean:

package com.test.jsp.beans;

public class TestBean {
    public String test;

    public String getTest() {
        return test;
    }

    public void setTest(String test) {
        this.test = test;
    }
}

How does java know to pass the value from the <input> tag to the setTest() method?

I would like to understand the inner workings of how they are linked, I assume reflection is used.

Does java look for the setter method or does it look for the variable?

Does the setter name need to be set + <input> name?

Does the setter need to contain exactly one parameter?

Does that parameter need to be the same name as the <input> tag?

Does the setter even need parameters?

Does capitalization matter?

etc...

There is a package java.beans in the official API.

A starting point for tool trying to analyze a bean class is the Introspector class having the getBeanInfo method, whose class doc states:

> If we don't find explicit BeanInfo on a class, we use low-level reflection to study the methods of the class and apply standard design patterns to identify property accessors, event sources, or public methods. We then proceed to analyze the class's superclass and add in the information from it (and possibly on up the superclass chain).

It clearly says that the (public) methods matter.

Compare with the PropertyDescriptor class of the package, which provides the meta information of a property, along with getReadMethod() and getWriteMethod() returning instances of the Reflection Method class.

The patterns for property accessor methods are described in chapter 7 and 8.3 of the Bean Specification, but you’ve already shown to know the basics. With the knowledge of the java.beans package, you may integrate classes deviating from the standard pattern, by providing explicit BeanInfo implementations.

Java is inspecting the request parameters. The askeriks sign on the property value means that all bean proiperties which match the request parameters will be set automaticaly when the form is submitted.

Does the setter name need to be set + <input> name? No, the name in the input element will be converted to request parameter than matched against the properties in the bean. No need to explicitly set the name of the setter method.