開發注意事項
1. 參數驗證
hibernate.validator
1.導入包
import org.hibernate.validator.constraints.NotBlank;
import javax.validation.constraints.AssertFalse;
import javax.validation.constraints.Pattern;
2.demo
@Getter
@Setter
@NoArgsConstructor
public class DemoModel {
@NotBlank(message="用戶名不能爲空")
private String userName;
@NotBlank(message="年齡不能爲空")
@Pattern(regexp="^[0-9]{1,2}$",message="年齡不正確")
private String age;
@AssertFalse(message = "必須爲false")
private Boolean isFalse;
/**
* 如果是空,則不校驗,如果不爲空,則校驗
*/
@Pattern(regexp="^[0-9]{4}-[0-9]{2}-[0-9]{2}$",message="出生日期格式不正確")
private String birthday;
}
3.結果返回
@RequestMapping("/demo2")
public void demo2(@RequestBody @Valid DemoModel demo, BindingResult result){
if(result.hasErrors()){
for (ObjectError error : result.getAllErrors()) {
System.out.println(error.getDefaultMessage());
}
}
}
4.傳入參數
{"userName":"dd","age":120,"isFalse":true,"birthday":"21010-21-12"}
5.輸出結果
出生日期格式不正確
必須爲false
年齡不正確
3. hibernate的校驗模式
1. 普通模式(默認爲該模式)
* 會校驗所有屬性,然後返回所有的驗證失敗信息。
2. 快速失敗返回模式只要有一個校驗失敗則返回。
3. 設置方式
// failFast: true 快速失敗返回模式,false 普通模式
ValidatorFactory validatorFactory = Validation.byProvider( HibernateValidator.class )
.configure()
.failFast( true )
.buildValidatorFactory();
Validator validator = validatorFactory.getValidator();
// hibernate.validator.fail_fast: true 快速失敗返回模式,false 普通模式
ValidatorFactory validatorFactory = Validation.byProvider( HibernateValidator.class )
.configure()
.addProperty( "hibernate.validator.fail_fast", "true" )
.buildValidatorFactory();
Validator validator = validatorFactory.getValidator();
- hibernate的校驗
- 配置hibernate Validator爲快速返回模式:
@Configuration
public class ValidatorConfiguration {
@Bean
public Validator validator(){
ValidatorFactory validatorFactory = Validation.byProvider( HibernateValidator.class )
.configure()
.addProperty( "hibernate.validator.fail_fast", "true" )
.buildValidatorFactory();
Validator validator = validatorFactory.getValidator();
return validator;
}
}
- 請求參數校驗
- 驗證請求參數時,在 @RequestBody DemoModel demo 之間加註解 @Valid,然後在後面加 BindindResult 即可;多個參數,可以添加多個 @Valid 和 BindindResult。
public void test()(@RequestBody @Valid DemoModel demo, BindingResult result)
public void test()(@RequestBody @Valid DemoModel demo, BindingResult result,@RequestBody @Valid DemoModel demo2, BindingResult result2)
- GET參數校驗(@RequestParam參數校驗)
1.controller
@RequestMapping(value = "/demo3", method = RequestMethod.GET)
public void demo3(@RequestParam(name = "grade", required = true) int grade,@RequestParam(name = "classroom", required = true) int classroom) {
System.out.println(grade + "," + classroom);
}
注:使用 @Valid 註解對 RequestParam 對應的參數時無效的,需要使用 @Validated 註解來使驗證生效。
2.MethodValidationPostProcessor 的 Bean
@Bean
public MethodValidationPostProcessor methodValidationPostProcessor() {
/**默認是普通模式,會返回所有的驗證不通過信息集合*/
return new MethodValidationPostProcessor();
}
3.或者可對 MethodValidationPostProcessor 進行設置 Validator
- 此時不是使用 Validator 進行驗證,Validator 的配置不起作用
@Bean
public MethodValidationPostProcessor methodValidationPostProcessor() {
MethodValidationPostProcessor postProcessor = new MethodValidationPostProcessor();
/**設置validator模式爲快速失敗返回*/
postProcessor.setValidator(validator());
return postProcessor;
}
@Bean
public Validator validator(){
ValidatorFactory validatorFactory = Validation.byProvider( HibernateValidator.class )
.configure()
.addProperty( "hibernate.validator.fail_fast", "true" )
.buildValidatorFactory();
Validator validator = validatorFactory.getValidator();
return validator;
}
4.方法所在的Controller上加註解 @Validated
@RequestMapping("/validation")
@RestController
@Validated
public class ValidationController {
/**如果只有少數對象,直接把參數寫到Controller層,然後在Controller層進行驗證就可以了。*/
@RequestMapping(value = "/demo3", method = RequestMethod.GET)
public void demo3(@Range(min = 1, max = 9, message = "年級只能從1-9")
@RequestParam(name = "grade", required = true)
int grade,
@Min(value = 1, message = "班級最小隻能1")
@Max(value = 99, message = "班級最大隻能99")
@RequestParam(name = "classroom", required = true)
int classroom) {
System.out.println(grade + "," + classroom);
}
}
5.返回驗證信息提示驗證不通過,拋出來 ConstraintViolationException 異常,使用統一捕獲異常處理
@ControllerAdvice
@Component
public class GlobalExceptionHandler {
@ExceptionHandler
@ResponseBody
@ResponseStatus(HttpStatus.BAD_REQUEST)
public String handle(ValidationException exception) {
if(exception instanceof ConstraintViolationException){
ConstraintViolationException exs = (ConstraintViolationException) exception;
Set<ConstraintViolation<?>> violations = exs.getConstraintViolations();
for (ConstraintViolation<?> item : violations) {
/**打印驗證不通過的信息*/
System.out.println(item.getMessage());
}
}
return "bad request, " ;
}
}
6.驗證
http://localhost:8080/validation/demo3?grade=18&classroom=888
3. model校驗
- model
@Data
public class Demo2 {
@Length(min = 5, max = 17, message = "length長度在[5,17]之間")
private String length;
/**@Size不能驗證Integer,適用於String, Collection, Map and arrays*/
@Size(min = 1, max = 3, message = "size在[1,3]之間")
private String age;
@Range(min = 150, max = 250, message = "range在[150,250]之間")
private int high;
@Size(min = 3,max = 5,message = "list的Size在[3,5]")
private List<String> list;
}
2.校驗
@Autowired
private Validator validator;
@RequestMapping("/demo3")
public void demo3(){
Demo2 demo2 = new Demo2();
demo2.setAge("111");
demo2.setHigh(150);
demo2.setLength("ABCDE");
demo2.setList(new ArrayList<String>(){{add("111");add("222");add("333");}});
Set<ConstraintViolation<Demo2>> violationSet = validator.validate(demo2);
for (ConstraintViolation<Demo2> model : violationSet) {
System.out.println(model.getMessage());
}
}
4. 對象級聯校驗
- 對象內部包含另一個對象作爲屬性,屬性上加 @Valid,可以驗證作爲屬性的對象內部的驗證
@Data
public class Demo2 {
@Size(min = 3,max = 5,message = "list的Size在[3,5]")
private List<String> list;
@NotNull
@Valid
private Demo3 demo3;
}
@Data
public class Demo3 {
@Length(min = 5, max = 17, message = "length長度在[5,17]之間")
private String extField;
}
校驗
/**前面配置了快速失敗返回的Bean*/
@Autowired
private Validator validator;
@RequestMapping("/demo3")
public void demo3(){
Demo2 demo2 = new Demo2();
demo2.setList(new ArrayList<String>(){{add("111");add("222");add("333");}});
Demo3 demo3 = new Demo3();
demo3.setExtField("22");
demo2.setDemo3(demo3);
Set<ConstraintViolation<Demo2>> violationSet = validator.validate(demo2);
for (ConstraintViolation<Demo2> model : violationSet) {
System.out.println(model.getMessage());
}
}
5. 分組校驗
- 校驗接口
public interface GroupA {
}
public interface GroupB {
}
@Data
public class Person {
@NotBlank
@Range(min = 1,max = Integer.MAX_VALUE,message = "必須大於0",groups = {GroupA.class})
/**用戶id*/
private Integer userId;
@NotBlank
@Length(min = 4,max = 20,message = "必須在[4,20]",groups = {GroupB.class})
/**用戶名*/
private String userName;
@NotBlank
@Range(min = 0,max = 100,message = "年齡必須在[0,100]",groups={Default.class})
/**年齡*/
private Integer age;
@Range(min = 0,max = 2,message = "性別必須在[0,2]",groups = {GroupB.class})
/**性別 0:未知;1:男;2:女*/
private Integer sex;
}
-
GroupA校驗字段userId
-
GroupB校驗字段userName、sex
-
Default校驗字段age(Default使Validator自帶的默認分組)
驗證
只驗證GroupA和GroupB的分組,以下示例代碼
@RequestMapping("/demo5")
public void demo5(){
Person p = new Person();
/**GroupA驗證不通過*/
p.setUserId(-12);
/**GroupA驗證通過*/
//p.setUserId(12);
p.setUserName("a");
p.setAge(110);
p.setSex(5);
Set<ConstraintViolation<Person>> validate = validator.validate(p, GroupA.class, GroupB.class);
for (ConstraintViolation<Person> item : validate) {
System.out.println(item);
}
}
@RequestMapping("/demo6")
public void demo6(@Validated({GroupA.class, GroupB.class}) Person p, BindingResult result){
if(result.hasErrors()){
List<ObjectError> allErrors = result.getAllErrors();
for (ObjectError error : allErrors) {
System.out.println(error);
}
}
}
4.組序列
- 指定組的驗證順序,前面組驗證不通過,後面組不驗證
// GroupA > GroupB > Default
@GroupSequence({GroupA.class, GroupB.class, Default.class})
public interface GroupOrder {
}
5. 自定義校驗器
- 大小寫校驗器
public enum CaseMode {
UPPER,
LOWER;
}
@Target( { ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = CheckCaseValidator.class)
@Documented
public @interface CheckCase {
String message() default "";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
CaseMode value();
}
public class CheckCaseValidator implements ConstraintValidator<CheckCase, String> {
private CaseMode caseMode;
public void initialize(CheckCase checkCase) {
this.caseMode = checkCase.value();
}
public boolean isValid(String s, ConstraintValidatorContext constraintValidatorContext) {
if (s == null) {
return true;
}
if (caseMode == CaseMode.UPPER) {
return s.equals(s.toUpperCase());
} else {
return s.equals(s.toLowerCase());
}
}
}
2.Demo
public class Demo{
@CheckCase(value = CaseMode.LOWER,message = "userName必須是小寫")
private String userName;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
}
- Validator配置
@Bean
public Validator validator(){
ValidatorFactory validatorFactory = Validation.byProvider( HibernateValidator.class )
.configure()
.addProperty( "hibernate.validator.fail_fast", "true" )
.buildValidatorFactory();
Validator validator = validatorFactory.getValidator();
return validator;
}
- 校驗測試
@RequestMapping("/demo4")
public void demo4(){
Demo demo = new Demo();
demo.setUserName("userName");
Set<ConstraintViolation<Demo>> validate = validator.validate(demo);
for (ConstraintViolation<Demo> dem : validate) {
System.out.println(dem.getMessage());
}
}
6. 自定義手動校驗工具類
public class ValidateUtil {
public ValidateUtil() {
}
public static String validateModel(Object obj) {
StringBuffer buffer = new StringBuffer();
Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
Set<ConstraintViolation<Object>> constraintViolations = validator.validate(obj, new Class[0]);
Iterator iter = constraintViolations.iterator();
while(iter.hasNext()) {
String message = ((ConstraintViolation)iter.next()).getMessage();
buffer.append(message).append("; ");
}
return buffer.toString();
}
}
7. 常見的註解
No. | 註解 | 解釋 |
---|---|---|
01 | @Null | 檢查該字段爲空 |
02 | @NotNull | 不能爲 null |
03 | @NotBlank | 不能爲空,檢查時會將空格忽略 |
04 | @NotEmpty | 不能爲空,這裏的空是指空字符串 |
05 | @AssertTrue | 用於boolwan字段,只能爲true |
06 | @AssertFalse | 用於boolwan字段,只能爲false |
07 | @CreditCardNumber | 對信用卡進行一個大致的校驗 |
08 | @DecimalMin(value) | 數值類型,只能小於或等於value |
09 | @DecimalMax(value) | 數值類型,只能大於或等於value |
10 | @Digits(integer=2,fraction=20) | 限制必須爲一個小數,整數部分位數不能超過integer,小數部分位數不能超過fraction |
11 | 檢查是否是一個有效的email地址 | |
12 | @Past | 檢查該字段的日期是否屬於過去的日期 |
13 | @Future | 檢查該字段的日期是否屬於將來的日期 |
14 | @Length(min=,max=) | 檢查該字段的長度是否在min和max之間,只能用於字符串 |
15 | @Size(min=,max=) | 檢查該字段的size是否在min和max之間,可以是字符串、數組、集合、map等 |
16 | @Min(value) | 小於等於value |
17 | @Max(value) | 大於等於value |
18 | @URL(protocol=,host,port) | 檢查是否是一個有效的URL,如果提供來protocol,host等,則該url還需滿足提供的條件 |
19 | @Valid | 該註解只要用於字段爲一個包含其他對象的集合或map或數組的字段,或該字段直接爲一個其他對象的引用(這樣在檢查當前對象的同時也會檢查該字段所引用的對象) |
2. 基本數據類型
Java的8種基本數據類型
關於Java的8種基本數據類型,其名稱、位數、默認值、取值範圍及示例如下表所示:
序號 | 數據類型 | 位數 | 默認值 | 取值範圍 | 舉例說明 |
---|---|---|---|---|---|
1 | byte(位) | 8 | 0 | -2^7 - 2^7-1 | byte b = 10; |
2 | short(短整數) | 16 | 0 | -2^15 - 2^15-1 | short s = 10; |
3 | int(整數) | 32 | 0 | -2^31 - 2^31-1 | int i = 10; |
4 | long(長整數) | 64 | 0 | -2^63 - 2^63-1 | long l = 10l; |
5 | float(單精度) | 32 | 0.0 | -2^31 - 2^31-1 | float f = 10.0f; |
6 | double(雙精度) | 64 | 0.0 | -2^63 - 2^63-1 | double d = 10.0d; |
7 | char(字符) | 16 | 空 | 0 - 2^16-1 | char c = ‘c’; |
8 | boolean(布爾值) | 8 | false | true、false | boolean b = true; |
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注:其中需要注意int對應的是Integer,char對應的Character,其他6個都是基本類型首字母大寫即可