1.pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project> <modelversion>4.0.0</modelversion> <parent> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-parent</artifactid> <version>2.2.1.RELEASE</version> <relativepath></relativepath> <!-- lookup parent from repository --> </parent> <groupid>qinfeng.zheng</groupid> <artifactid>learn-pagequery</artifactid> <version>0.0.1-SNAPSHOT</version> <name>learn-pagequery</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-web</artifactid> </dependency> <dependency> <groupid>org.mybatis.spring.boot</groupid> <artifactid>mybatis-spring-boot-starter</artifactid> <version>1.3.2</version> </dependency> <dependency> <groupid>mysql</groupid> <artifactid>mysql-connector-java</artifactid> <version>5.1.47</version> <scope>runtime</scope> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-test</artifactid> <scope>test</scope> <exclusions> <exclusion> <groupid>org.junit.vintage</groupid> <artifactid>junit-vintage-engine</artifactid> </exclusion> </exclusions> </dependency> <dependency> <groupid>com.github.pagehelper</groupid> <artifactid>pagehelper-spring-boot-starter</artifactid> <version>1.2.12</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-maven-plugin</artifactid> </plugin> </plugins> </build> </project>
2.application.peroperties
#pagehelper
pagehelper.helper-dialect=mysql
pagehelper.params=count=countSql
pagehelper.reasonable=true
pagehelper.support-methods-arguments= true#mysql
spring.datasource.driver-class-name = com.mysql.jdbc.Driver
spring.datasource.url= jdbc:mysql://120.79.xx.xx:3306/test?useUnicode=yes&characterEncoding= UTF-8&useSSL=false
spring.datasource.username = root
spring.datasource.password = 1212212
3.엔티티 클래스
public class Country implements Serializable { private static final long serialVersionUID = 6569081236403751407L; private int id; private String countryname; private String countrycode; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getCountryname() { return countryname; } public void setCountryname(String countryname) { this.countryname = countryname; } public String getCountrycode() { return countrycode; } public void setCountrycode(String countrycode) { this.countrycode = countrycode; } }
4, 매퍼 인터페이스 클래스
@Mapper public interface CountryMapper { @Select("select * from country") List<country> findAll(); }</country>
5.cotroller 클래스
@RestController public class CountryController { @Autowired private CountryMapper countryMapper; @GetMapping("/findAll") public List<country> findAll(@RequestParam(defaultValue = "1") Integer pageNum, @RequestParam(defaultValue = "20") Integer pageSize) { PageHelper.startPage(pageNum, pageSize); List<country> countries = countryMapper.findAll(); Page page = (Page) countries; System.out.println("每页展示条数:" + page.getPageSize()); System.out.println("总条数:" + page.getTotal()); System.out.println("当前页:" + page.getPageNum()); System.out.println("总页数:" + page.getPages()); return countries; } }</country></country>
7.
공식 데이터를 직접 복사
drop table country if exists; create table country ( id int primary key auto_increment, countryname varchar(32), countrycode varchar(2) ); insert into country (id, countryname, countrycode) values(1,'Angola','AO'); insert into country (id, countryname, countrycode) values(2,'Afghanistan','AF'); insert into country (id, countryname, countrycode) values(3,'Albania','AL'); insert into country (id, countryname, countrycode) values(4,'Algeria','DZ'); insert into country (id, countryname, countrycode) values(5,'Andorra','AD'); insert into country (id, countryname, countrycode) values(6,'Anguilla','AI'); insert into country (id, countryname, countrycode) values(7,'Antigua and Barbuda','AG'); insert into country (id, countryname, countrycode) values(8,'Argentina','AR'); insert into country (id, countryname, countrycode) values(9,'Armenia','AM'); insert into country (id, countryname, countrycode) values(10,'Australia','AU'); insert into country (id, countryname, countrycode) values(11,'Austria','AT'); insert into country (id, countryname, countrycode) values(12,'Azerbaijan','AZ'); insert into country (id, countryname, countrycode) values(13,'Bahamas','BS'); insert into country (id, countryname, countrycode) values(14,'Bahrain','BH'); insert into country (id, countryname, countrycode) values(15,'Bangladesh','BD'); insert into country (id, countryname, countrycode) values(16,'Barbados','BB'); insert into country (id, countryname, countrycode) values(17,'Belarus','BY'); insert into country (id, countryname, countrycode) values(18,'Belgium','BE'); insert into country (id, countryname, countrycode) values(19,'Belize','BZ'); insert into country (id, countryname, countrycode) values(20,'Benin','BJ'); insert into country (id, countryname, countrycode) values(21,'Bermuda Is.','BM'); insert into country (id, countryname, countrycode) values(22,'Bolivia','BO'); insert into country (id, countryname, countrycode) values(23,'Botswana','BW'); insert into country (id, countryname, countrycode) values(24,'Brazil','BR'); insert into country (id, countryname, countrycode) values(25,'Brunei','BN'); insert into country (id, countryname, countrycode) values(26,'Bulgaria','BG'); insert into country (id, countryname, countrycode) values(27,'Burkina-faso','BF'); insert into country (id, countryname, countrycode) values(28,'Burma','MM'); insert into country (id, countryname, countrycode) values(29,'Burundi','BI'); insert into country (id, countryname, countrycode) values(30,'Cameroon','CM'); insert into country (id, countryname, countrycode) values(31,'Canada','CA'); insert into country (id, countryname, countrycode) values(32,'Central African Republic','CF'); insert into country (id, countryname, countrycode) values(33,'Chad','TD'); insert into country (id, countryname, countrycode) values(34,'Chile','CL'); insert into country (id, countryname, countrycode) values(35,'China','CN'); insert into country (id, countryname, countrycode) values(36,'Colombia','CO'); insert into country (id, countryname, countrycode) values(37,'Congo','CG'); insert into country (id, countryname, countrycode) values(38,'Cook Is.','CK'); insert into country (id, countryname, countrycode) values(39,'Costa Rica','CR'); insert into country (id, countryname, countrycode) values(40,'Cuba','CU'); insert into country (id, countryname, countrycode) values(41,'Cyprus','CY'); insert into country (id, countryname, countrycode) values(42,'Czech Republic','CZ'); insert into country (id, countryname, countrycode) values(43,'Denmark','DK'); insert into country (id, countryname, countrycode) values(44,'Djibouti','DJ'); insert into country (id, countryname, countrycode) values(45,'Dominica Rep.','DO'); insert into country (id, countryname, countrycode) values(46,'Ecuador','EC'); insert into country (id, countryname, countrycode) values(47,'Egypt','EG'); insert into country (id, countryname, countrycode) values(48,'EI Salvador','SV'); insert into country (id, countryname, countrycode) values(49,'Estonia','EE'); insert into country (id, countryname, countrycode) values(50,'Ethiopia','ET'); insert into country (id, countryname, countrycode) values(51,'Fiji','FJ'); insert into country (id, countryname, countrycode) values(52,'Finland','FI'); insert into country (id, countryname, countrycode) values(53,'France','FR'); insert into country (id, countryname, countrycode) values(54,'French Guiana','GF'); insert into country (id, countryname, countrycode) values(55,'Gabon','GA'); insert into country (id, countryname, countrycode) values(56,'Gambia','GM'); insert into country (id, countryname, countrycode) values(57,'Georgia','GE'); insert into country (id, countryname, countrycode) values(58,'Germany','DE'); insert into country (id, countryname, countrycode) values(59,'Ghana','GH'); insert into country (id, countryname, countrycode) values(60,'Gibraltar','GI'); insert into country (id, countryname, countrycode) values(61,'Greece','GR'); insert into country (id, countryname, countrycode) values(62,'Grenada','GD'); insert into country (id, countryname, countrycode) values(63,'Guam','GU'); insert into country (id, countryname, countrycode) values(64,'Guatemala','GT'); insert into country (id, countryname, countrycode) values(65,'Guinea','GN'); insert into country (id, countryname, countrycode) values(66,'Guyana','GY'); insert into country (id, countryname, countrycode) values(67,'Haiti','HT'); insert into country (id, countryname, countrycode) values(68,'Honduras','HN'); insert into country (id, countryname, countrycode) values(69,'Hongkong','HK'); insert into country (id, countryname, countrycode) values(70,'Hungary','HU'); insert into country (id, countryname, countrycode) values(71,'Iceland','IS'); insert into country (id, countryname, countrycode) values(72,'India','IN'); insert into country (id, countryname, countrycode) values(73,'Indonesia','ID'); insert into country (id, countryname, countrycode) values(74,'Iran','IR'); insert into country (id, countryname, countrycode) values(75,'Iraq','IQ'); insert into country (id, countryname, countrycode) values(76,'Ireland','IE'); insert into country (id, countryname, countrycode) values(77,'Israel','IL'); insert into country (id, countryname, countrycode) values(78,'Italy','IT'); insert into country (id, countryname, countrycode) values(79,'Jamaica','JM'); insert into country (id, countryname, countrycode) values(80,'Japan','JP'); insert into country (id, countryname, countrycode) values(81,'Jordan','JO'); insert into country (id, countryname, countrycode) values(82,'Kampuchea (Cambodia )','KH'); insert into country (id, countryname, countrycode) values(83,'Kazakstan','KZ'); insert into country (id, countryname, countrycode) values(84,'Kenya','KE'); insert into country (id, countryname, countrycode) values(85,'Korea','KR'); insert into country (id, countryname, countrycode) values(86,'Kuwait','KW'); insert into country (id, countryname, countrycode) values(87,'Kyrgyzstan','KG'); insert into country (id, countryname, countrycode) values(88,'Laos','LA'); insert into country (id, countryname, countrycode) values(89,'Latvia','LV'); insert into country (id, countryname, countrycode) values(90,'Lebanon','LB'); insert into country (id, countryname, countrycode) values(91,'Lesotho','LS'); insert into country (id, countryname, countrycode) values(92,'Liberia','LR'); insert into country (id, countryname, countrycode) values(93,'Libya','LY'); insert into country (id, countryname, countrycode) values(94,'Liechtenstein','LI'); insert into country (id, countryname, countrycode) values(95,'Lithuania','LT'); insert into country (id, countryname, countrycode) values(96,'Luxembourg','LU'); insert into country (id, countryname, countrycode) values(97,'Macao','MO'); insert into country (id, countryname, countrycode) values(98,'Madagascar','MG'); insert into country (id, countryname, countrycode) values(99,'Malawi','MW'); insert into country (id, countryname, countrycode) values(100,'Malaysia','MY'); insert into country (id, countryname, countrycode) values(101,'Maldives','MV'); insert into country (id, countryname, countrycode) values(102,'Mali','ML'); insert into country (id, countryname, countrycode) values(103,'Malta','MT'); insert into country (id, countryname, countrycode) values(104,'Mauritius','MU'); insert into country (id, countryname, countrycode) values(105,'Mexico','MX'); insert into country (id, countryname, countrycode) values(106,'Moldova, Republic of','MD'); insert into country (id, countryname, countrycode) values(107,'Monaco','MC'); insert into country (id, countryname, countrycode) values(108,'Mongolia','MN'); insert into country (id, countryname, countrycode) values(109,'Montserrat Is','MS'); insert into country (id, countryname, countrycode) values(110,'Morocco','MA'); insert into country (id, countryname, countrycode) values(111,'Mozambique','MZ'); insert into country (id, countryname, countrycode) values(112,'Namibia','NA'); insert into country (id, countryname, countrycode) values(113,'Nauru','NR'); insert into country (id, countryname, countrycode) values(114,'Nepal','NP'); insert into country (id, countryname, countrycode) values(115,'Netherlands','NL'); insert into country (id, countryname, countrycode) values(116,'New Zealand','NZ'); insert into country (id, countryname, countrycode) values(117,'Nicaragua','NI'); insert into country (id, countryname, countrycode) values(118,'Niger','NE'); insert into country (id, countryname, countrycode) values(119,'Nigeria','NG'); insert into country (id, countryname, countrycode) values(120,'North Korea','KP'); insert into country (id, countryname, countrycode) values(121,'Norway','NO'); insert into country (id, countryname, countrycode) values(122,'Oman','OM'); insert into country (id, countryname, countrycode) values(123,'Pakistan','PK'); insert into country (id, countryname, countrycode) values(124,'Panama','PA'); insert into country (id, countryname, countrycode) values(125,'Papua New Cuinea','PG'); insert into country (id, countryname, countrycode) values(126,'Paraguay','PY'); insert into country (id, countryname, countrycode) values(127,'Peru','PE'); insert into country (id, countryname, countrycode) values(128,'Philippines','PH'); insert into country (id, countryname, countrycode) values(129,'Poland','PL'); insert into country (id, countryname, countrycode) values(130,'French Polynesia','PF'); insert into country (id, countryname, countrycode) values(131,'Portugal','PT'); insert into country (id, countryname, countrycode) values(132,'Puerto Rico','PR'); insert into country (id, countryname, countrycode) values(133,'Qatar','QA'); insert into country (id, countryname, countrycode) values(134,'Romania','RO'); insert into country (id, countryname, countrycode) values(135,'Russia','RU'); insert into country (id, countryname, countrycode) values(136,'Saint Lueia','LC'); insert into country (id, countryname, countrycode) values(137,'Saint Vincent','VC'); insert into country (id, countryname, countrycode) values(138,'San Marino','SM'); insert into country (id, countryname, countrycode) values(139,'Sao Tome and Principe','ST'); insert into country (id, countryname, countrycode) values(140,'Saudi Arabia','SA'); insert into country (id, countryname, countrycode) values(141,'Senegal','SN'); insert into country (id, countryname, countrycode) values(142,'Seychelles','SC'); insert into country (id, countryname, countrycode) values(143,'Sierra Leone','SL'); insert into country (id, countryname, countrycode) values(144,'Singapore','SG'); insert into country (id, countryname, countrycode) values(145,'Slovakia','SK'); insert into country (id, countryname, countrycode) values(146,'Slovenia','SI'); insert into country (id, countryname, countrycode) values(147,'Solomon Is','SB'); insert into country (id, countryname, countrycode) values(148,'Somali','SO'); insert into country (id, countryname, countrycode) values(149,'South Africa','ZA'); insert into country (id, countryname, countrycode) values(150,'Spain','ES'); insert into country (id, countryname, countrycode) values(151,'Sri Lanka','LK'); insert into country (id, countryname, countrycode) values(152,'St.Lucia','LC'); insert into country (id, countryname, countrycode) values(153,'St.Vincent','VC'); insert into country (id, countryname, countrycode) values(154,'Sudan','SD'); insert into country (id, countryname, countrycode) values(155,'Suriname','SR'); insert into country (id, countryname, countrycode) values(156,'Swaziland','SZ'); insert into country (id, countryname, countrycode) values(157,'Sweden','SE'); insert into country (id, countryname, countrycode) values(158,'Switzerland','CH'); insert into country (id, countryname, countrycode) values(159,'Syria','SY'); insert into country (id, countryname, countrycode) values(160,'Taiwan','TW'); insert into country (id, countryname, countrycode) values(161,'Tajikstan','TJ'); insert into country (id, countryname, countrycode) values(162,'Tanzania','TZ'); insert into country (id, countryname, countrycode) values(163,'Thailand','TH'); insert into country (id, countryname, countrycode) values(164,'Togo','TG'); insert into country (id, countryname, countrycode) values(165,'Tonga','TO'); insert into country (id, countryname, countrycode) values(166,'Trinidad and Tobago','TT'); insert into country (id, countryname, countrycode) values(167,'Tunisia','TN'); insert into country (id, countryname, countrycode) values(168,'Turkey','TR'); insert into country (id, countryname, countrycode) values(169,'Turkmenistan','TM'); insert into country (id, countryname, countrycode) values(170,'Uganda','UG'); insert into country (id, countryname, countrycode) values(171,'Ukraine','UA'); insert into country (id, countryname, countrycode) values(172,'United Arab Emirates','AE'); insert into country (id, countryname, countrycode) values(173,'United Kiongdom','GB'); insert into country (id, countryname, countrycode) values(174,'United States of America','US'); insert into country (id, countryname, countrycode) values(175,'Uruguay','UY'); insert into country (id, countryname, countrycode) values(176,'Uzbekistan','UZ'); insert into country (id, countryname, countrycode) values(177,'Venezuela','VE'); insert into country (id, countryname, countrycode) values(178,'Vietnam','VN'); insert into country (id, countryname, countrycode) values(179,'Yemen','YE'); insert into country (id, countryname, countrycode) values(180,'Yugoslavia','YU'); insert into country (id, countryname, countrycode) values(181,'Zimbabwe','ZW'); insert into country (id, countryname, countrycode) values(182,'Zaire','ZR'); insert into country (id, countryname, countrycode) values(183,'Zambia','ZM');
좋아, 모든 것이 준비되었습니다. springboot 프로젝트를 시작하고, 브라우저에 접속하고, 컨트롤러의 인쇄에 주의하세요
첫 번째 요청:
컨트롤러 인쇄:
두 번째 요청:
컨트롤러 인쇄:
확인, 확인이 완료되었습니다! 완벽한! ! !
보충 사항:
페이징 기능을 수행할 때 프런트 엔드 페이징 플러그인에는 일반적으로 현재 페이지 수, 총 항목 수 및 총 페이지 수와 같은 일부 데이터가 필요합니다. 플러그인의 요구 사항을 완전히 충족할 수 있는 PageInfo 개체를 참조할 수 있습니다.
@GetMapping("/findAll") public PageInfo<country> findAll(@RequestParam(defaultValue = "1") Integer pageNum, @RequestParam(defaultValue = "20") Integer pageSize) { PageHelper.startPage(pageNum, pageSize); List<country> countries = countryMapper.findAll(); // Page page = (Page) countries; // System.out.println("每页展示条数:" + page.getPageSize()); // System.out.println("总条数:" + page.getTotal()); // System.out.println("当前页:" + page.getPageNum()); // System.out.println("总页数:" + page.getPages()); PageInfo<country> result = new PageInfo(countries); return result; }</country></country></country>
요청 테스트:
PageInfo 클래스의 소스 코드를 살펴보면 프런트엔드 페이징 플러그인에 대한 포괄적인 속성 지원이 있다는 것을 어렵지 않게 찾을 수 있습니다.
private int pageNum; // 当前页码 private int pageSize; // 每页展示的多少条数据 private int size; // 数据总条数 private int startRow; private int endRow; private int pages; // 总共多少页 private int prePage; // 前一页 private int nextPage; // 后一页 private boolean isFirstPage; private boolean isLastPage; private boolean hasPreviousPage; private boolean hasNextPage; private int navigatePages; private int[] navigatepageNums; private int navigateFirstPage; private int navigateLastPage;
위 내용은 Springboot2에 페이지 헬퍼를 통합하는 방법의 상세 내용입니다. 자세한 내용은 PHP 중국어 웹사이트의 기타 관련 기사를 참조하세요!

javadevelopmentisnotentirelyplatform-IndectionentDuetoSeveralFactors.1) JVMVARIATIONSAFFERFFERFORMANDBEHAVIORACROSSDIFFERENTOS.2) nativelibrariesViajniintrictionPlatform-specificiss.3) filepathsandsystempropertiesdifferbetweenplatectry. 4)

Java 코드는 다른 플랫폼에서 실행할 때 성능 차이가 있습니다. 1) JVM의 구현 및 최적화 전략은 OracleJDK 및 OpenJDK와 같이 다릅니다. 2) 메모리 관리 및 스레드 스케줄링과 같은 운영 체제의 특성도 성능에 영향을 미칩니다. 3) 적절한 JVM을 선택하여 JVM 매개 변수 및 코드 최적화를 조정하여 성능을 향상시킬 수 있습니다.

Java'SplatformIndenceHASLIMITATIONSINTERFORMANTOWORHEAD, 버전 컴포팅 가능성, 도전 과제, 플랫폼-특이 적 식품, 및 JVMINSTALLATION/MAYMENDENT.ThesefacteThe "WriteOnce, Runanywhere"

Platform IndependenCealLowsProgramStorunannyplatformwithoutModification, whileCross-PlatformDevelopmentRequiressomplatformspecificAdJustments.platformIndence, PreemplifiedByjava, enableStalExecutionButmayPromiseperformance.cross-platformd

jitcompilationinjavaenhancesperformance는 platformindence.1) ItdynamicallyTransLatesByTecodeIntonativeMachinecodeatimeTime, 최적화 FREQUELTEREDCODE.2) TheJVMREMAINSPLATFORM- Independent, 허용 THEMEJAVAAPPLITIONTORUNONDIFFEREN을 허용합니다

javaispopularforcross-platformdesktopapplicationsduetoits "writeonce, runanywhere"철학

Java에서 플랫폼 별 코드를 작성하는 이유에는 특정 운영 체제 기능에 대한 액세스, 특정 하드웨어와 상호 작용하고 성능 최적화가 포함됩니다. 1) JNA 또는 JNI를 사용하여 Windows 레지스트리에 액세스하십시오. 2) JNI를 통한 Linux 특이 적 하드웨어 드라이버와 상호 작용; 3) 금속을 사용하여 JNI를 통해 MacOS의 게임 성능을 최적화하십시오. 그럼에도 불구하고 플랫폼 별 코드를 작성하면 코드의 이식성에 영향을 미치고 복잡성을 높이며 잠재적으로 성능 오버 헤드 및 보안 위험을 초래할 수 있습니다.

Java는 Cloud-Native Applications, Multi-Platform 배포 및 교차 운용성을 통해 플랫폼 독립성을 더욱 향상시킬 것입니다. 1) Cloud Native Applications는 Graalvm 및 Quarkus를 사용하여 시작 속도를 높입니다. 2) Java는 임베디드 장치, 모바일 장치 및 양자 컴퓨터로 확장됩니다. 3) Graalvm을 통해 Java는 Python 및 JavaScript와 같은 언어와 완벽하게 통합되어 언어 교차 수용 가능성을 향상시킵니다.


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Eclipse를 SAP NetWeaver 애플리케이션 서버와 통합합니다.

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시각적 웹 개발 도구
