FreeMarker代码分析第十篇

FreeMarker代码分析第十篇

2021SC@SDUSC

FreeMarker代码分析第十篇

• beans包
• • AllowAllMemberAccessPolicy.java
  • • 代码分析
  • APIModel.java
  • • 代码分析
  • ArrayModel.java
  • • 代码分析

beans包 AllowAllMemberAccessPolicy.java 代码分析

package freemarker.ext.beans;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

final class AllowAllMemberAccessPolicy implements MemberAccessPolicy {
    public static final AllowAllMemberAccessPolicy INSTANCE = new AllowAllMemberAccessPolicy();

    private AllowAllMemberAccessPolicy() {
    }

    public static final ClassMemberAccessPolicy CLASS_POLICY_INSTANCE = new ClassMemberAccessPolicy() {
        @Override
        public boolean isMethodExposed(Method method) {
            return true;
        }

        @Override
        public boolean isConstructorExposed(Constructor constructor) {
            return true;
        }

        @Override
        public boolean isFieldExposed(Field field) {
            return true;
        }
    };

    @Override
    public ClassMemberAccessPolicy forClass(Class contextClass) {
        return CLASS_POLICY_INSTANCE;
    }

    @Override
    public boolean isToStringAlwaysExposed() {
        return true;
    }
}

APIModel.java 代码分析

package freemarker.ext.beans;


final class APIModel extends BeanModel {

    APIModel(Object object, BeansWrapper wrapper) {
        super(object, wrapper, false);
    }

    protected boolean isMethodsShadowItems() {
        return true;
    }
    
}

ArrayModel.java 代码分析

package freemarker.ext.beans;

import java.lang.reflect.Array;

import freemarker.ext.util.ModelFactory;
import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateCollectionModel;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateModelIterator;
import freemarker.template.TemplateSequenceModel;


public class ArrayModel
extends
    BeanModel
implements
    TemplateCollectionModel,
    TemplateSequenceModel {
    static final ModelFactory FACTORY =
        new ModelFactory()
        {
            @Override
            public TemplateModel create(Object object, ObjectWrapper wrapper) {
                return new ArrayModel(object, (BeansWrapper) wrapper);
            }
        };
        
    // array对象的数量
    private final int length;

    
    public ArrayModel(Object array, BeansWrapper wrapper) {
        super(array, wrapper);
        Class clazz = array.getClass();
        if (!clazz.isArray())
            throw new IllegalArgumentException("Object is not an array, it's " + array.getClass().getName());
        length = Array.getLength(array);
    }


    @Override
    public TemplateModelIterator iterator() {
        return new Iterator();
    }

    @Override
    public TemplateModel get(int index)
    throws TemplateModelException {
        try {
            return wrap(Array.get(object, index));
        } catch (IndexOutOfBoundsException e) {
            return null; 
//            throw new TemplateModelException("Index out of bounds: " + index);
        }
    }
    
    private class Iterator
    implements 
        TemplateSequenceModel,
        TemplateModelIterator {
        private int position = 0;

        @Override
        public boolean hasNext() {
            return position < length;
        }

        @Override
        public TemplateModel get(int index)
        throws TemplateModelException {
            return ArrayModel.this.get(index);
        }

        @Override
        public TemplateModel next()
        throws TemplateModelException {
            return position < length ? get(position++) : null;
        }

        @Override
        public int size() {
            return ArrayModel.this.size();
        }
    }

    @Override
    public int size() {
        return length;
    }

    @Override
    public boolean isEmpty() {
        return length == 0;
    }
}