java注解方式参数校验
1、注解类NotEmpty.java空值校验
package com.cmbc.umm.core.common.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Documented
@Inherited
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface NotEmpty {
//String value() default "";
}
2、注解类CheckValue.java正则表达式校验和空值校验
package com.cmbc.umm.core.common.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Documented
@Inherited
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface CheckValue {
String value() default "";
}
3、解析工具类AnnotationUtil.java
package com.cmbc.umm.core.common.util;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.cmbc.umm.core.common.annotation.CheckValue;
import com.cmbc.umm.core.common.annotation.NotEmpty;
public class AnnotationUtil {
private static final Logger logger = LoggerFactory.getLogger(AnnotationUtil.class);
/**
* 校验格式是否正确，如果@CheckValue() 没有参数，则校验是否为空
* 例子：@CheckValue("^[A-Za-z0-9_-]{1,32}$") 校验数字、字母、下划线1到32位 ： @CheckValue()
* 校验字段是否为空
*
* @param obj
* @return 如果返回null表示：校验通过
*/
public static String checkValue(Object obj) {
return parseAnnotation(CheckValue.class, obj, true);
}
/**
* 校验是否为空
*
* @param obj
* @return 如果返回null表示：校验通过
*/
public static String checkEmpty(Object obj) {
return parseAnnotation(NotEmpty.class, obj, true);
}
private static String parseAnnotation(Class aClazz, Object obj, boolean hasParent) {
StringBuilder sb = new StringBuilder();
boolean flag = false;
Class clazz = obj.getClass();
Field[] fields = clazz.getDeclaredFields();
Field[] bothField = fields;
if (hasParent) {
Class superClazz = clazz.getSuperclass();
Field[] superFields = superClazz.getDeclaredFields();
bothField = (Field[]) ArrayUtils.addAll(fields, superFields);
}
for (Field field : bothField) {
Annotation annotation = field.getAnnotation(aClazz);
if (annotation == null)
continue;
field.setAccessible(true);
try {
if (annotation instanceof CheckValue) {
CheckValue cv = (CheckValue) annotation;
String regex = cv.value();
if (StringUtils.isEmpty(regex)) {
// 输入的正则表达式为空，所以不做校验
// continue;
// NotEmpty ne = (NotEmpty)annotation;
Object oValue = field.get(obj);
if (oValue == null) {
sb.append("字段" + field.getName() + "不能为null|");
flag = true;
} else {
if (oValue instanceof String) {
String value = (String) oValue;
if (StringUtils.isBlank(value)) {
sb.append("字段" + field.getName() + "不能为空|");
flag = true;
}
} else {
logger.info("字段" + field.getName() + "不是字符串，不能判断是否为空");
}
}
} else {
Pattern pattern = Pattern.compile(regex);
String value = (String) field.get(obj);
Matcher m = pattern.matcher(value);
if (!m.matches()) {
sb.append("字段" + field.getName() + "格式错误|");
flag = true;
}
}
} else if (annotation instanceof NotEmpty) {
Object oValue = field.get(obj);
if (oValue == null) {
sb.append("字段" + field.getName() + "不能为null|");
flag = true;
} else {
if (oValue instanceof String) {
String value = (String) oValue;
if (StringUtils.isBlank(value)) {
sb.append("字段" + field.getName() + "不能为空|");
flag = true;
}
} else {
logger.info("字段" + field.getName() + "不是字符串，不能判断是否为空");
}
}
}
} catch (Exception e) {
sb.append(e.getMessage());
flag = true;
logger.error("解析注解出错：", e);
// e.printStackTrace();
}
}
if (flag) {
return sb.toString();
} else {
return null;
}
}
}
4、测试
1）People.java
package test;
import com.cmbc.commons.annotation.CheckValue;
import com.cmbc.commons.annotation.NotEmpty;
public class People {
@CheckValue("^[A-Za-z0-9_-]{13,32}$")
private String id;
@NotEmpty
private String name;
@CheckValue
private int age;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "People [id=" + id + ", name=" + name + ", age=" + age + "]";
}
}
2）Student.java
package test;
import com.cmbc.commons.annotation.CheckValue;
public class Student extends People{
@CheckValue
private String clazzNo;
public String getClazzNo() {
return clazzNo;
}
public void setClazzNo(String clazzNo) {
this.clazzNo = clazzNo;
}
}
3）测试代码
package test;
import java.util.Map;
import com.cmbc.commons.utils.AnnotationUtil;
import com.cmbc.epay.umm.utils.EfficentDevUtil;
public class Test {
private String name;
public static void main(String[] args) {
Student p = new Student();
p.setId("1111");
p.setName("");
p.setClazzNo(" ");
String s = AnnotationUtil.checkValue(p);
System.out.println(s);
}
}