JFinal源码--获取表单数据

使用request获取表单中数据的方法

<input type="text" name="user.name"/>

String name = request.getParameter("user.name");
User user = new User();
user.setName(name);

1.JFinal中可以直接将表单的数据注入到Model中

User u = getModel（User.class);

getModel方法是继承自Controller，注入的具体实现在ModelInjector类中

/**
     * Get model from http request.
     */
    public <T> T getModel(Class<T> modelClass) {
        return (T)ModelInjector.inject(modelClass, request, false);
    }

2.ModelInjector 表单数据注入的具体实现类

    通过传入的 model.class 得到 model类的所有方法，然后找到属性所对应的set方法，将request取到的值转换为对应的数据类型，最后把值赋给model类

final class ModelInjector {
    
    public static <T> T inject(Class<?> modelClass, HttpServletRequest request, boolean skipConvertError) {
        String modelName = modelClass.getSimpleName();
        return inject(modelClass, StringKit.firstCharToLowerCase(modelName), request, skipConvertError);
    }
    
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public static final <T> T inject(Class<?> modelClass, String modelName, HttpServletRequest request, boolean skipConvertError) {
        Object model = null;
        try {
            model = modelClass.newInstance();//采用反射创建一个model的实例
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        
        if (model instanceof Model)
            injectActiveRecordModel((Model)model, modelName, request, skipConvertError);//继承Model类注入表单数据的实现
        else
            injectCommonModel(model, modelName, request, modelClass, skipConvertError);//普通Moedl类注入表单数据的实现
        
        return (T)model;
    }
    
    private static final void injectCommonModel(Object model, String modelName, HttpServletRequest request, Class<?> modelClass, boolean skipConvertError) {
        Method[] methods = modelClass.getMethods();//获得Model类的所有方法
        for (Method method : methods) {
            String methodName = method.getName();//方法名 
            //只有实现了属性对应的set方法并且传入的参数为一个的时候才能把form里的数据注入到对应的model属性上
            if (methodName.startsWith("set") == false)    // only setter method   
                continue;
            
            Class<?>[] types = method.getParameterTypes();
            if (types.length != 1)                        // only one parameter
                continue;
            
            String attrName = methodName.substring(3);
            String value = request.getParameter(modelName + "." + StringKit.firstCharToLowerCase(attrName));//拼接出model.属性（JFinal默认form里数据名必须是类名.属性）这样才能用request取到对应的值
            if (value != null) {
                try {
                    method.invoke(model, TypeConverter.convert(types[0], value));//TypeConverter将value值转换成类属性对应的数据类型，执行model的method方法将value set到model的属性上
                } catch (Exception e) {
                    if (skipConvertError == false)
                    throw new RuntimeException(e);
                }
            }
        }
    }
    
    @SuppressWarnings("rawtypes")
    private static final void injectActiveRecordModel(Model<?> model, String modelName, HttpServletRequest request, boolean skipConvertError) {
        TableInfo tableInfo = TableInfoMapping.me().getTableInfo(model.getClass());//TableInfo保存有Model类的所有属性，相当于一个Model实例
        
        String modelNameAndDot = modelName + ".";
        
        Map<String, String[]> parasMap = request.getParameterMap();
        for (Entry<String, String[]> e : parasMap.entrySet()) {//request中的数据是以key-value的方式保存的，遍历提交来form的所有数据
            String paraKey = e.getKey();
            if (paraKey.startsWith(modelNameAndDot)) {//满足“类.属性”格式的的数据才能被识别保存到model中
                String paraName = paraKey.substring(modelNameAndDot.length());
                Class colType = tableInfo.getColType(paraName);//从tableInfo中查找 属性对应的type
                if (colType == null)
                    throw new ActiveRecordException("The model attribute " + paraKey + " is not exists.");
                String[] paraValue = e.getValue();//取数据
                try {
                    // Object value = Converter.convert(colType, paraValue != null ? paraValue[0] : null);
                    Object value = paraValue[0] != null ? TypeConverter.convert(colType, paraValue[0]) : null;//将数据转换为正确类型
                    model.set(paraName, value);//保存数据到model里
                } catch (Exception ex) {
                    if (skipConvertError == false)
                        throw new RuntimeException("Can not convert parameter: " + modelNameAndDot + paraName, ex);
                }
            }
        }
    }
}