JFinal源碼--獲取表單數據

使用request獲取表單中數據的方法

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

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

1.JFinal中能夠直接將表單的數據注入到Model中

User u = getModel（User.class);

getModel方法是繼承自Controller，注入的具體實如今ModelInjector類中

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

2.ModelInjector 表單數據注入的具體實現類

    經過傳入的 model.class 獲得 model類的全部方法，而後找到屬性所對應的set方法，將request取到的值轉換爲對應的數據類型，最後把值賦給model類

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();//採用反射建立一個model的實例
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        
        if (model instanceof Model)
            injectActiveRecordModel((Model)model, modelName, request, skipConvertError);//繼承Model類注入表單數據的實現
        else
            injectCommonModel(model, modelName, request, modelClass, skipConvertError);//普通Moedl類注入表單數據的實現
        
        return (T)model;
    }
    
    private static final void injectCommonModel(Object model, String modelName, HttpServletRequest request, Class<?> modelClass, boolean skipConvertError) {
        Method[] methods = modelClass.getMethods();//得到Model類的全部方法
        for (Method method : methods) {
            String methodName = method.getName();//方法名 
            //只有實現了屬性對應的set方法而且傳入的參數爲一個的時候才能把form裏的數據注入到對應的model屬性上
            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.屬性（JFinal默認form裏數據名必須是類名.屬性）這樣才能用request取到對應的值
            if (value != null) {
                try {
                    method.invoke(model, TypeConverter.convert(types[0], value));//TypeConverter將value值轉換成類屬性對應的數據類型，執行model的method方法將value set到model的屬性上
                } 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類的全部屬性，至關於一個Model實例
        
        String modelNameAndDot = modelName + ".";
        
        Map<String, String[]> parasMap = request.getParameterMap();
        for (Entry<String, String[]> e : parasMap.entrySet()) {//request中的數據是以key-value的方式保存的，遍歷提交來form的全部數據
            String paraKey = e.getKey();
            if (paraKey.startsWith(modelNameAndDot)) {//知足「類.屬性」格式的的數據才能被識別保存到model中
                String paraName = paraKey.substring(modelNameAndDot.length());
                Class colType = tableInfo.getColType(paraName);//從tableInfo中查找 屬性對應的type
                if (colType == null)
                    throw new ActiveRecordException("The model attribute " + paraKey + " is not exists.");
                String[] paraValue = e.getValue();//取數據
                try {
                    // Object value = Converter.convert(colType, paraValue != null ? paraValue[0] : null);
                    Object value = paraValue[0] != null ? TypeConverter.convert(colType, paraValue[0]) : null;//將數據轉換爲正確類型
                    model.set(paraName, value);//保存數據到model裏
                } catch (Exception ex) {
                    if (skipConvertError == false)
                        throw new RuntimeException("Can not convert parameter: " + modelNameAndDot + paraName, ex);
                }
            }
        }
    }
}