导入工具类和方法的代码
- 过滤中文乱码数据
- HTML转义
- DAOFactory
- JDBC连接池
- UUID工具类
- c3p0.xml配置文件
这些代码都可以在我的博客分类：代码库中找到！
分类模块
首先，我们来做分类模块吧
创建实体Category
private String id;
private String name;
private String description;
//各种setter、getter
在数据库创建表
CREATE TABLE category (
id VARCHAR(40) PRIMARY KEY,
name VARCHAR(10) NOT NULL UNIQUE ,
description VARCHAR(255)
);
编写CategoryDAO
/**
* 分类模块
* 1：添加分类
* 2：查找分类
* 3：修改分类
*
*
* */
public class CategoryImpl {
public void addCategory(Category category) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "INSERT INTO category (id, name, description) VALUES(?,?,?)";
try {
queryRunner.update(sql, new Object[]{category.getId(), category.getName(), category.getDescription()});
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
public Category findCategory(String id) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT * FROM category WHERE id=?";
try {
Category category = (Category) queryRunner.query(sql, id, new BeanHandler(Category.class));
return category;
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
public List<Category> getAllCategory() {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT * FROM category";
try {
List<Category> categories = (List<Category>) queryRunner.query(sql, new BeanListHandler(Category.class));
return categories;
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
测试DAO
public class demo {
@Test
public void add() {
Category category = new Category();
category.setId("2");
category.setName("数据库系列");
category.setDescription("这是数据库系列");
CategoryImpl category1 = new CategoryImpl();
category1.addCategory(category);
}
@Test
public void find() {
String id = "1";
CategoryImpl category1 = new CategoryImpl();
Category category = category1.findCategory(id);
System.out.println(category.getName());
}
@Test
public void getAll() {
CategoryImpl category1 = new CategoryImpl();
List<Category> categories = category1.getAllCategory();
for (Category category : categories) {
System.out.println(category.getName());
}
}
}
抽取成DAO接口
public interface CategoryDao {
void addCategory(Category category);
Category findCategory(String id);
List<Category> getAllCategory();
}
后台页面的添加分类
- 在超链接上，绑定显示添加分类的页面
<a href="${pageContext.request.contextPath}/background/addCategory.jsp" target="body">添加分类</a>
- 显示添加分类的JSP页面
<form action="${pageContext.request.contextPath}/CategoryServlet?method=add" method="post">
分类名称：<input type="text" name="name"><br>
分类描述：<textarea name="description"></textarea><br>
<input type="submit" value="提交">
</form>
- 处理添加分类的Servlet
if (method.equals("add")) {
try {
//把浏览器带过来的数据封装到bean中
Category category = WebUtils.request2Bean(request, Category.class);
category.setId(WebUtils.makeId());
service.addCategory(category);
request.setAttribute("message", "添加分类成功！");
} catch (Exception e) {
request.setAttribute("message","添加分类失败");
e.printStackTrace();
}
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
- 效果：