初始化项目：添加src和doc文件夹，放入指定基础文件

scr/CustomerController.java

@@ -0,0 +1,152 @@
+package com.training.api;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.training.api.dto.CreateCustomerRequest;
+import com.training.model.Customer;
+import com.training.service.CustomerService;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.util.List;
+
+
+@WebServlet("/api/customers/*") // 关键修改：使用通配符*来匹配路径参数
+public class CustomerController extends HttpServlet {
+    private final ObjectMapper objectMapper;
+    private final CustomerService customerService;
+
+    public CustomerController() {
+        this.objectMapper = new ObjectMapper();
+        this.customerService = new CustomerService();
+    }
+
+
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
+            throws ServletException, IOException {
+        try {
+            resp.setContentType("application/json");
+            resp.setCharacterEncoding("UTF-8");
+
+            String pathInfo = req.getPathInfo(); // 获取 /api/customers 之后的路径部分，例如 "/1"
+
+            if (pathInfo == null || pathInfo.equals("/")) {
+                // 获取所有客户
+                List<Customer> customers = customerService.findAll();
+                objectMapper.writeValue(resp.getOutputStream(), customers);
+            } else {
+                // 尝试根据ID获取单个客户
+                try {
+                    long id = Long.parseLong(pathInfo.substring(1)); // 去掉开头的 '/'
+                    Customer customer = customerService.findById(id);
+                    if (customer != null) {
+                        objectMapper.writeValue(resp.getOutputStream(), customer);
+                    } else {
+                        resp.setStatus(HttpServletResponse.SC_NOT_FOUND); // 404 Not Found
+                        resp.getWriter().write("{\"error\": \"客户不存在\"}");
+                    }
+                } catch (NumberFormatException e) {
+                    resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); // 400 Bad Request
+                    resp.getWriter().write("{\"error\": \"无效的客户ID格式\"}");
+                }
+            }
+        } catch (Exception e) {
+            resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+            e.printStackTrace();
+            resp.getWriter().write("{\"error\": \"获取客户信息失败: " + e.getMessage() + "\"}");
+        }
+    }
+
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
+            throws ServletException, IOException {
+        try {
+            resp.setContentType("application/json");
+            resp.setCharacterEncoding("UTF-8");
+
+            CreateCustomerRequest createCustomerRequest = objectMapper.readValue(req.getInputStream(), CreateCustomerRequest.class);
+
+            Customer customer = customerService.create(createCustomerRequest);
+
+            resp.setStatus(HttpServletResponse.SC_CREATED); // 201 Created
+            objectMapper.writeValue(resp.getOutputStream(), customer);
+
+        } catch (Exception e) {
+            resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+            e.printStackTrace();
+            resp.getWriter().write("{\"error\": \"创建客户失败: " + e.getMessage() + "\"}");
+        }
+    }
+
+
+    @Override
+    protected void doPut(HttpServletRequest req, HttpServletResponse resp)
+            throws ServletException, IOException {
+        try {
+            resp.setContentType("application/json");
+            resp.setCharacterEncoding("UTF-8");
+
+            String pathInfo = req.getPathInfo();
+            // 检查路径是否包含ID，例如 "/1"
+            if (pathInfo == null || !pathInfo.matches("/\\d+")) {
+                resp.setStatus(HttpServletResponse.SC_BAD_REQUEST);
+                resp.getWriter().write("{\"error\": \"请求URL必须包含有效的客户ID，例如 /api/customers/1\"}");
+                return;
+            }
+
+            long customerId = Long.parseLong(pathInfo.substring(1)); // 解析ID
+            CreateCustomerRequest updateRequest = objectMapper.readValue(req.getInputStream(), CreateCustomerRequest.class);
+
+            Customer updatedCustomer = customerService.update(customerId, updateRequest);
+
+            if (updatedCustomer != null) {
+                objectMapper.writeValue(resp.getOutputStream(), updatedCustomer);
+            } else {
+                resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
+                resp.getWriter().write("{\"error\": \"要更新的客户不存在\"}");
+            }
+
+        } catch (Exception e) {
+            resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+            e.printStackTrace();
+            resp.getWriter().write("{\"error\": \"更新客户失败: " + e.getMessage() + "\"}");
+        }
+    }
+
+
+    @Override
+    protected void doDelete(HttpServletRequest req, HttpServletResponse resp)
+            throws ServletException, IOException {
+        try {
+            resp.setContentType("application/json");
+            resp.setCharacterEncoding("UTF-8");
+
+            String pathInfo = req.getPathInfo();
+            if (pathInfo == null || !pathInfo.matches("/\\d+")) {
+                resp.setStatus(HttpServletResponse.SC_BAD_REQUEST);
+                resp.getWriter().write("{\"error\": \"请求URL必须包含有效的客户ID，例如 /api/customers/1\"}");
+                return;
+            }
+
+            long customerId = Long.parseLong(pathInfo.substring(1));
+            boolean deleted = customerService.deleteById(customerId);
+
+            if (deleted) {
+                resp.setStatus(HttpServletResponse.SC_NO_CONTENT); // 204 No Content
+            } else {
+                resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
+                resp.getWriter().write("{\"error\": \"要删除的客户不存在\"}");
+            }
+
+        } catch (Exception e) {
+            resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+            e.printStackTrace();
+            resp.getWriter().write("{\"error\": \"删除客户失败: " + e.getMessage() + "\"}");
+        }
+    }
+}