How to integrate pagehelper in Springboot2
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. Entity class
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, mapper interface class
@Mapper
public interface CountryMapper {
@Select("select * from country")
List<country> findAll();
}</country>5.cotroller class
@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.Test data
Directly copy the official data
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');
Okay, everything is ready, start the springboot project, access the browser, pay attention to the controller printing
First request:
controller prints:
Second request:
controller Print:
OK, verification completed! Perfect! ! !
Supplement:
When doing the paging function, the front-end paging plug-in generally needs some data such as the current page number, the total number of items, and the total number of pages. In this case, you can refer to PageInfo. Object, which can fully meet the paging requirements of the plug-in.
@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>Request test:
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;
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