Initial MyBatis support for Spring-Data (specifically a sample repository and Pagination).

PageI.java

import java.util.Collection;
import java.util.List;
import java.util.ListIterator;

import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.Pageable;

/**
 * Extension class between spring data commons and java.util.List that is 
 * required to get MyBatis to use it as a return value.
 * 
 * The list section is all undefined.
 * 
 * @author sheenobu
 *
 * @param <T> The Type of the contained entity.
 */
public class PageI<T> extends PageImpl<T> implements List<T> {

	public PageI(List<T> content) {
		super(content);
	}

	public PageI(List<T> content,Pageable pageable, int total) {
		super(content,pageable,total);
	}
	
	private static final long serialVersionUID = 1L;

	@Override
	public boolean add(T e) {
		throw new UnsupportedOperationException();
	}

	@Override
	public void add(int index, T element) {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean addAll(Collection<? extends T> c) {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean addAll(int index, Collection<? extends T> c) {
		throw new UnsupportedOperationException();
	}

	@Override
	public void clear() {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean contains(Object o) {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean containsAll(Collection<?> c) {
		throw new UnsupportedOperationException();
	}

	@Override
	public T get(int index) {
		throw new UnsupportedOperationException();
	}

	@Override
	public int indexOf(Object o) {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean isEmpty() {
		throw new UnsupportedOperationException();
	}

	@Override
	public int lastIndexOf(Object o) {
		throw new UnsupportedOperationException();
	}

	@Override
	public ListIterator<T> listIterator() {
		throw new UnsupportedOperationException();
	}

	@Override
	public ListIterator<T> listIterator(int index) {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean remove(Object o) {
		throw new UnsupportedOperationException();
	}

	@Override
	public T remove(int index) {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean removeAll(Collection<?> c) {
		throw new UnsupportedOperationException();
	}

	@Override
	public boolean retainAll(Collection<?> c) {
		throw new UnsupportedOperationException();
	}

	@Override
	public T set(int index, T element) {
		throw new UnsupportedOperationException();
	}

	@Override
	public int size() {
		throw new UnsupportedOperationException();
	}

	@Override
	public List<T> subList(int fromIndex, int toIndex) {
		throw new UnsupportedOperationException();
	}

	@Override
	public Object[] toArray() {
		throw new UnsupportedOperationException();
	}

	@Override
	public <T> T[] toArray(T[] a) {
		throw new UnsupportedOperationException();
	}

	
}

Person.java

import java.io.Serializable;

public class Person implements Serializable{
	

	private static final long serialVersionUID = 1L;
	private String firstName;	
	private String lastName;	
	private String id;
	
	private String username;
	private String password;
	public String getFirstName() {
		return firstName;
	}
	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}
	public String getLastName() {
		return lastName;
	}
	public void setLastName(String lastName) {
		this.lastName = lastName;
	}
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	
	
	

}

PersonRepository.java

import java.util.List;

import org.springframework.data.domain.Pageable;
import org.springframework.data.repository.CrudRepository;

public interface PersonRepository extends CrudRepository<Person,String> {

//all listed are implemented YaY.

	@Override
	public long count();

	@Override
	public List<Person> findAll();
	
	@Override
	public Person findOne(String id);

	public PageI<Person> findAll(Pageable page);
	
}

PersonRepository.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="PersonRepository">

	<select id="findAll" resultType="Person" parameterType="org.springframework.data.domain.Pageable" >
		SELECT 
			uuid,
			firstName,
			lastName,
			userID as username,
			password	
		 from person
                  <!-- TODO: USE if and foreach for sorting and pagination -->
	</select>
	
	<select id="findOne" resultType="Person" parameterType="String">
		SELECT 
			uuid,
			firstName,
			lastName,
			userID as username,
			password		
		 from person
		 where
		 	uuid = #{id}
	</select>
	
	<select id="count" resultType="int">
		SELECT 
			count(*)
		from person		
	</select>

</mapper>

SpringDataMyBatisPlugin.java

import java.sql.ResultSet;
import java.sql.Statement;
import java.util.List;
import java.util.Properties;

import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Plugin;
import org.apache.ibatis.plugin.Signature;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.springframework.data.domain.Pageable;

/**
 * MyBatis plugin which allows functions of the form
 *  
 * 	: {@link PageI}<T> someFunction(...,{@link Pageable}  pageable,...) 
 * 
 * to work properly using spring-datas {@link Pageable} and {@link Page} interfaces.
 * 
 * @author sheenobu
 *
 */
//ISSUE 1: bad query transformation.
//ISSUE 2: The function must use PageI instead of Page, otherwise mybatis will choke.
@Intercepts({ @Signature(type = Executor.class, method = "query", args = 
	{ MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class } )})
public class SpringDataMyBatisPlugin implements Interceptor {

	@Override
	public Object intercept(Invocation arg0) throws Throwable {
		boolean pageable = false;
		Pageable pageableObject = null;
		MappedStatement stmt = null;
				
		for(Object o : arg0.getArgs())
		{
			if(o != null)
			{
				if(Pageable.class.isAssignableFrom(o.getClass())) {
					pageable = true;
					pageableObject = (Pageable) o;					
				}
				if(o instanceof MappedStatement)
				{
					stmt = (MappedStatement)o;					
				}
			}
		}
		
		Object ret = arg0.proceed();

		if(pageable && pageableObject != null && stmt != null) {
			int total  = -1;
			
			Executor exec = (Executor) arg0.getTarget();
			Statement sqlstmt = exec.getTransaction().getConnection().createStatement();
			
			
			// This is a bit shady. I might want to replace it by finding a similar function on the same
			//   mapper. For example: FunctionA => countOfFunctionA
			
			//Convert the select ... from ... statement to a count statement. 
			//TODO: remove paginating LIMITS and such.
			ResultSet s = sqlstmt.executeQuery(stmt.getSqlSource().getBoundSql(null).getSql().replace('\n', ' ')
					.replaceFirst("[S|s][E|e][L|l][E|e][C|c][T\t]\\s+.*[F|f][R|r][O|o][M|m]","SELECT count(*) from "));
			
			s.next();
			total = s.getShort(1); 
	
			PageI<?> pi = new PageI<Object>((List)ret, pageableObject,total);			
			return pi;
		}

		return ret;
	}

	@Override
	public Object plugin(Object arg0) {
		return Plugin.wrap(arg0,(Interceptor) this);
	}

	@Override
	public void setProperties(Properties arg0) {
		
	}
}

Is this still working with spring boot 1.4 and mybatis 3.4.1 ?