Android注解方式实现表单校验 _android

千磨万击还坚劲，任尔东西南北风。这篇文章主要讲述Android注解方式实现表单校验相关的知识，希望能为你提供帮助。
在开发中总会遇到输入框的输入规则限制比如电话输入框电话号码的校验，密码规则的校验等，我们通常做法是提交操作时对每个输入框的输入内容进行校验，很多的if else ，代码看起来很乱，其实我们可以用反射注解的方式去声明一些判断规则这样会更好，代码可读性更强。
java反射文章推荐：http://www.jianshu.com/p/5b3acad0f025

下面我们通过一个例子去讲解注解方式去实现表达式的校验

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这个包下定义的是注解实体类，每一个类都是一个注解规则，如Index类代码：

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这个包下都是一些javabean, 如AttrBean代码：

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BaseBean基础类，每个bean是一个规则javabean类，

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结果回调类

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处理回调校验结果

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上面主要是校验器和工具类：

public class ValidateUtil {

/**
* 设置校验view的信息
* @param view
* @param isEditText
* @param msg
* @param validateResult
*/
private static void setViewInfo(Object view, boolean isEditText, String msg, IValidateResult validateResult) {
if (isEditText) {
validateResult.onValidateError(msg, ((EditText) view));
} else {
validateResult.onValidateError(msg, null);
}
}

/**
* 不可为空
* @param view
* @param isEt
* @param msg
* @param validateResult
* @return
*/
public static boolean notNull(Object view, boolean isEt, String msg, IValidateResult validateResult) {
if (TextUtils.isEmpty(((TextView) view).getText().toString())) {
setViewInfo(view, isEt, msg, validateResult);
return true;
}
return false;
}

/**
* 判断是否为空
* @param view
* @return
*/
public static boolean isNull(Object view) {
if (view == null)
throw new NullPointerException("view can not be null");
if (TextUtils.isEmpty(((TextView) view).getText().toString())) {
return true;
}
return false;
}

/**
* 根据正则表达式校验
* @param view
* @param isEt
* @param bean
* @param validateResult
* @return
*/
public static boolean checkPattern(Object view, boolean isEt, PatternBean bean, IValidateResult validateResult) {
if (isNull(view)) return true;

Pattern r = Pattern.compile(bean.pattern);
Matcher m = r.matcher(((TextView) view).getText().toString());
if (!m.matches()) {
setViewInfo(view, isEt, bean.msg, validateResult);
return true;
}
return false;
}

/**
* 最大长度校验
* @param view
* @param isEt
* @param bean
* @param validateResult
* @return
*/
public static boolean maxLenght(Object view, boolean isEt, LengthBean bean, IValidateResult validateResult) {
if (isNull(view)) return true;

if (((TextView) view).getText().toString().length() > bean.length) {
setViewInfo(view, isEt, bean.msg, validateResult);
return true;
}
return false;
}
}

public class ValidateManager {
private static final String TAG = "ValidateManager";
/**
* 注册的页面
*/
private static Map< Object, List< AttrBean> > registList = new HashMap< > ();
/**
* 类型
*/
private static final String TYPE_NOTNULL = "NotNull";
private static final String TYPE_PATTERN = "PATTERN";
private static final String TYPE_MAXLENGTH = "MAXLENGTH";
private static final String TYPE_MINLENGTH = "MINLENGTH";
private static final String TYPE_PASSWORDFIRST = "PASSWORD_FIRST";
private static final String TYPE_PASSWORDSECOND = "PASSWORD_SECOND";
private static final String TYPE_SKIP = "SKIP";

public static void check(Object activity, boolean isSkip, IValidateResult validateResult) {
if (activity == null || validateResult == null) return;
List< AttrBean> list = registList.get(activity);
if (list == null) return;
for (AttrBean attrBean : list) {
if (attrBean.index == null) {
return;
}
}
Collections.sort(list, new Comparator< AttrBean> () {
public int compare(AttrBean arg0, AttrBean arg1) {
return arg0.index.compareTo(arg1.index);
}
});
for (AttrBean attrBean : list) {
for (Basebean bean : attrBean.annos) {
if (isSkip) {
if (TYPE_SKIP.equals(attrBean.annos.getLast().type)) {
break;
}
}
if (TYPE_NOTNULL.equals(bean.type)) {
if (ValidateUtil.notNull(attrBean.view, attrBean.isEditText, bean.msg, validateResult)) {
return;
}
} else if (TYPE_PATTERN.equals(bean.type)) {
if (ValidateUtil.checkPattern(attrBean.view, attrBean.isEditText, (PatternBean) bean, validateResult)) {
return;
}
} else if (TYPE_MAXLENGTH.equals(bean.type)) {
if (ValidateUtil.maxLenght(attrBean.view, attrBean.isEditText, (LengthBean) bean, validateResult)) {
return;
}
} else if (TYPE_MINLENGTH.equals(bean.type)) {
if (ValidateUtil.minLenght(attrBean.view, attrBean.isEditText, (LengthBean) bean, validateResult)) {
return;
}
} else if (TYPE_PASSWORDFIRST.equals(bean.type)) {
if (ValidateUtil.isNull(attrBean.view)) {
return;
}
pwd1Attr = attrBean;
} else if (TYPE_PASSWORDSECOND.equals(bean.type)) {
if (ValidateUtil.password(attrBean, pwd1Attr, (PasswordBean) bean, validateResult)) {
return;
}
pwd1Attr = null;
}
}
}
validateResult.onValidateSuccess();
pwd1Attr = null;
}

private static AttrBean pwd1Attr = null;

private static class ValidateRegRunnable implements Runnable {
Object target;

public ValidateRegRunnable(Object target) {
this.target = target;
}

@Override
public void run() {
try {
Class clazz = target.getClass();

for (Field field : clazz.getDeclaredFields()) {
if (field.isAnnotationPresent(NotNull.class) ||
field.isAnnotationPresent(Pattern.class) ||
field.isAnnotationPresent(MaxLength.class) ||
field.isAnnotationPresent(MinLength.class) ||
field.isAnnotationPresent(Index.class) ||
field.isAnnotationPresent(PasswordFirst.class) ||
field.isAnnotationPresent(PasswordSecond.class)) {

if (field.getType() != EditText.class) {
throw new RuntimeException("annotation must be on the EditText");
}
field.setAccessible(true);
List< AttrBean> editTextMap = registList.get(target);
if (editTextMap == null) {
editTextMap = new LinkedList< > ();
registList.put(target, editTextMap);
}
AttrBean attr = new AttrBean();
attr.name = field.getName();
attr.view = field.get(target);

if (field.getType() == EditText.class) {
attr.isEditText = true;
} else if (field.getType() == TextView.class) {
attr.isEditText = false;
}
if (attr.annos == null) {
attr.annos = new LinkedList< > ();
}
editTextMap.add(attr);

if (field.isAnnotationPresent(NotNull.class))
attr.annos.add(validateType(field, TYPE_NOTNULL));
if (field.isAnnotationPresent(Pattern.class))
attr.annos.add(validateType(field, TYPE_PATTERN));
if (field.isAnnotationPresent(MaxLength.class)) {
attr.annos.add(validateType(field, TYPE_MAXLENGTH));
if (attr.view != null & & attr.isEditText) {
int length = field.getAnnotation(MaxLength.class).length();
((EditText) attr.view).setFilters(new InputFilter[]{new InputFilter.LengthFilter(length)});
}
}
if (field.isAnnotationPresent(MinLength.class))
attr.annos.add(validateType(field, TYPE_MINLENGTH));
if (field.isAnnotationPresent(PasswordFirst.class)) {
attr.annos.add(validateType(field, TYPE_PASSWORDFIRST));
if (attr.view != null & & attr.isEditText) {
((EditText) attr.view).setTransformationMethod(PasswordTransformationMethod.getInstance());
}
}
if (field.isAnnotationPresent(PasswordSecond.class)) {
attr.annos.add(validateType(field, TYPE_PASSWORDSECOND));
if (attr.view != null & & attr.isEditText) {
((EditText) attr.view).setTransformationMethod(PasswordTransformationMethod.getInstance());
}
}
if (field.isAnnotationPresent(Index.class))
attr.index = field.getAnnotation(Index.class).value();
if (field.isAnnotationPresent(Skip.class))
attr.annos.add(validateType(field, TYPE_SKIP));
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}

/**
* 根据不同类型校验
* @param field
* @param type
* @return
* @throws IllegalAccessException
*/
private static Basebean validateType(Field field, String type) throws IllegalAccessException {
if (type.equals(TYPE_NOTNULL)) {
NotNull notnull = field.getAnnotation(NotNull.class);
NotNullBean bean = new NotNullBean();
bean.msg = notnull.msg();
bean.type = type;
return bean;
} else if (type.equals(TYPE_PATTERN)) {
Pattern re = field.getAnnotation(Pattern.class);
PatternBean reBean = new PatternBean();
reBean.msg = re.msg();
reBean.type = TYPE_PATTERN;
reBean.pattern = re.pattern();
return reBean;
} else if (type.equals(TYPE_MAXLENGTH)) {
MaxLength anno = field.getAnnotation(MaxLength.class);
LengthBean bean = new LengthBean();
bean.msg = anno.msg();
bean.type = TYPE_MAXLENGTH;
bean.length = anno.length();
return bean;
} else if (type.equals(TYPE_MINLENGTH)) {
MinLength anno = field.getAnnotation(MinLength.class);
LengthBean bean = new LengthBean();
bean.msg = anno.msg();
bean.type = TYPE_MINLENGTH;
bean.length = anno.length();
return bean;
} else if (type.equals(TYPE_PASSWORDFIRST)) {
PasswordBean bean = new PasswordBean();
bean.type = TYPE_PASSWORDFIRST;
return bean;
} else if (type.equals(TYPE_PASSWORDSECOND)) {
PasswordSecond anno = field.getAnnotation(PasswordSecond.class);
PasswordBean bean = new PasswordBean();
bean.msg = anno.msg();
bean.type = TYPE_PASSWORDSECOND;
return bean;
} else if (type.equals(TYPE_SKIP)) {
Basebean bean = new Basebean();
bean.type = TYPE_SKIP;
return bean;
}

return null;
}

/**
* 注册
* @param target
*/
public static void regist(final Object target) {
new Thread(new ValidateRegRunnable(target)).start();
}

/**
* 解注册
* @param target
*/
public static void unregist(Object target) {
registList.remove(target);
}
}

我只贴出了部分代码，可以根据项目实际需求去添加规则，再把相应的校验器代码扩展到这个类里。
我们在主页面使用按照正常的注解方式去实现如下：

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index是校验的顺序，需要正则表达式校验的输入框我们通过pattern去通过正则表达式去实现，minLength和maxLength是最小最大长度校验
完成后调用ValidateManager.check(this , isSkip , this); 实现校验功能，经过回调处理（isSkip是否可以忽略不校验此项）