Spring Integration JPA and REST

Spring Integration JPA and REST

here's a little sample project i put together to illustrate how to expose JPA objects via REST using Spring Integration.  it's a bit rough but it does the following;
- PUT a new entity
- GET an entity by id
- GET all entities

here's the entity;

package de.incompleteco.spring.jpa.domain;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="simple_entity")
public class SimpleEntity implements Serializable {

 private static final long serialVersionUID = 1l;

 @Id
 @GeneratedValue(strategy=GenerationType.AUTO)
 private Long id;
 
 @Column
 private String stuff;

 public Long getId() {
  return id;
 }

 public void setId(Long id) {
  this.id = id;
 }

 public String getStuff() {
  return stuff;
 }

 public void setStuff(String stuff) {
  this.stuff = stuff;
 }

 @Override
 public String toString() {
  return "SimpleEntity [id=" + id + ", stuff=" + stuff + "]";
 }
 
}

here's the entity manager factory;

here's the Spring Integration for the JPA service

here's the Spring Integration for the HTTP endpoint

and here's a test showing it all

package de.incompleteco.spring.jpa;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static org.springframework.test.web.servlet.setup.MockMvcBuilders.webAppContextSetup;

import javax.annotation.Resource;

import org.codehaus.jackson.map.ObjectMapper;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.http.MediaType;
import org.springframework.test.context.ActiveProfiles;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.web.context.WebApplicationContext;

import de.incompleteco.spring.jpa.domain.SimpleEntity;

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration({"classpath:/META-INF/spring/*-context.xml"})
@ActiveProfiles("junit")
public class IntegrationTest {

 @Resource
 private WebApplicationContext context;
 
 private ObjectMapper mapper;
 
 private MockMvc mvc;
 
 @Before
 public void before() throws Exception {
  //setup
  mapper = new ObjectMapper();//json
  mvc = webAppContextSetup(context).build();  
 }

 @Test
 public void test() throws Exception {
  //create an object
  SimpleEntity entity = new SimpleEntity();
  entity.setStuff("hello world");
  //convert
  String json = mapper.writeValueAsString(entity);
  //execute
  MvcResult result = mvc.perform(put("/simpleEntity").contentType(MediaType.APPLICATION_JSON).content(json))
   .andExpect(status().isOk()).andReturn();
  //now convert back
  SimpleEntity resultEntity = mapper.readValue(result.getResponse().getContentAsByteArray(), SimpleEntity.class);
  //now check
  assertTrue(resultEntity.getId() > 0);
  assertEquals(entity.getStuff(),resultEntity.getStuff());
  //retrieve by the id
  result = mvc.perform(get("/simpleEntity").param("id", resultEntity.getId().toString()))
   .andExpect(status().isOk()).andReturn();
  //now convert
  SimpleEntity retrievedEntity = mapper.readValue(result.getResponse().getContentAsByteArray(), SimpleEntity.class);
  //now check
  assertEquals(entity.getStuff(),retrievedEntity.getStuff());
  //retrieve all
  result = mvc.perform(get("/simpleEntity"))
    .andExpect(status().isOk()).andReturn();
  //now it *should* be an array of SimpleEntity
  SimpleEntity[] entities = mapper.readValue(result.getResponse().getContentAsByteArray(),SimpleEntity[].class);
  //test
  assertNotNull(entities);
  assertTrue(entities.length > 0);
  
 }
}

if you want the code, it's here; https://github.com/incomplete-code/spring-integration-jpa

Spring Integration HTTP Endpoint and Id's

Spring Integration HTTP Endpoint and Id's

a quick note - if you're using Spring Integration HTTP Gateways (more than one) in an application context, give them unique Id's.

otherwise you'll get some strange bean exceptions on startup.

Spring Integration HTTP - Testing

Spring Integration HTTP - testing

with the new Spring 3.2, there's an even easier way to test Spring MVC and, in turn, Spring Integration HTTP endpoints; MockMvc.

here's a sample Spring Integration HTTP endpoint that, when invoked, logs the passed parameter.  (really quick and dirty)

now to test this

package de.incompleteco.spring.integration;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static org.springframework.test.web.servlet.setup.MockMvcBuilders.webAppContextSetup;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.web.context.WebApplicationContext;

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration({"classpath:/META-INF/spring/integration-context.xml"})
public class IntegrationContextTest {

 @Autowired
 private WebApplicationContext context;
 
 @Test
 public void test() throws Exception {
  //setup the mock mvc
  MockMvc mockMvc = webAppContextSetup(context).build();
  //execute
  mockMvc.perform(put("/log").content("something to log")).andExpect(status().isOk());
 }
 
}

Spring Integration Http Inbound Gateway and Path

Spring Integration Http Inbound Gateway and Path

a little reminder for myself; when setting the path attribute on the inbound-gateway, always create the UriPathHandlerMapping bean...

Spring Integration, Content-Length and WebSphere

Spring Integration, Content-Length and WebSphere

one little annoying thing i discovered the other day was that WebSphere (either app server or the http server) truncates the outbound response to the content-length value.  so, if you're content-length value is less than your content, you'll get a truncated body content.  nice...

this becomes a little bit of a problem when using Spring Integration 2.1.x out of the box.  if you're using the http-inbound-gateway, and you don't set which request headers to map, it will map all of them, including content-length.  This header then stays on the message (unless manipulated later) and is passed out, with the value set by the original request.  

the fix for this is straight-forward, set the mapped-request-headers value.  that way, only the specific header names will be set.  otherwise, you can enrich the headers on the way out, but that becomes a little more tricky when specifying the content length.