《Pro Spring Boot 2》第五章：Data Access with Spring Boot

package com.apress.todo.repository;

import com.apress.todo.domain.ToDo;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.stereotype.Repository;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.temporal.TemporalAccessor;
import java.util.*;

@Repository
public class ToDoRepository implements CommonRepository<ToDo> {

    private static final String SQL_INSERT = "insert into todo (id, description, created, modified, completed) values (:id,:description,:created,:modified,:completed)";
    private static final String SQL_QUERY_FIND_ALL = "select id, description, created, modified, completed from todo";
    private static final String SQL_QUERY_FIND_BY_ID = SQL_QUERY_FIND_ALL + " where id = :id";
    private static final String SQL_UPDATE = "update todo set description = :description, modified = :modified, completed = :completed where id = :id";
    private static final String SQL_DELETE = "delete from todo where id = :id";

    private final NamedParameterJdbcTemplate jdbcTemplate;

    public ToDoRepository(NamedParameterJdbcTemplate jdbcTemplate){
        this.jdbcTemplate = jdbcTemplate;
    }

    private RowMapper<ToDo> toDoRowMapper = (ResultSet rs, int rowNum) -> {
        ToDo toDo = new ToDo();
        toDo.setId(rs.getString("id"));
        toDo.setDescription(rs.getString("description"));
        toDo.setModified(rs.getTimestamp("modified").toLocalDateTime());
        toDo.setCreated(rs.getTimestamp("created").toLocalDateTime());
        toDo.setCompleted(rs.getBoolean("completed"));
        return toDo;
    };

    @Override
    public ToDo save(final ToDo domain) {
        ToDo result = findById(domain.getId());
        if(result != null){
            result.setDescription(domain.getDescription());
            result.setCompleted(domain.isCompleted());
            result.setModified(LocalDateTime.now());
            return upsert(result, SQL_UPDATE);
        }
        return upsert(domain,SQL_INSERT);
    }

    private ToDo upsert(final ToDo toDo, final String sql){
        Map<String, Object> namedParameters = new HashMap<>();
        namedParameters.put("id",toDo.getId());
        namedParameters.put("description",toDo.getDescription());
        namedParameters.put("created",java.sql.Timestamp.valueOf(toDo.getCreated()));
        namedParameters.put("modified",java.sql.Timestamp.valueOf(toDo.getModified()));
        namedParameters.put("completed",toDo.isCompleted());

        this.jdbcTemplate.update(sql,namedParameters);

        return findById(toDo.getId());
    }

    @Override
    public Iterable<ToDo> save(Collection<ToDo> domains) {
        domains.forEach( this::save);
        return findAll();
    }

    @Override
    public void delete(final ToDo domain) {
        Map<String, String> namedParameters = Collections.singletonMap("id", domain.getId());
        this.jdbcTemplate.update(SQL_DELETE,namedParameters);
    }

    @Override
    public ToDo findById(String id) {
        try {
            Map<String, String> namedParameters = Collections.singletonMap("id", id);
            return this.jdbcTemplate.queryForObject(SQL_QUERY_FIND_BY_ID, namedParameters, toDoRowMapper);
        } catch (EmptyResultDataAccessException ex) {
            return null;
        }
    }

    @Override
    public Iterable<ToDo> findAll() {
        return this.jdbcTemplate.query(SQL_QUERY_FIND_ALL, toDoRowMapper);
    }


}

package com.apress.todo.repository;

import com.apress.todo.domain.ToDo;
import org.springframework.data.repository.CrudRepository;


public interface ToDoRepository extends CrudRepository<ToDo,String> {

}

package com.apress.todo.domain;


import lombok.Data;
import lombok.NoArgsConstructor;
import org.hibernate.annotations.GenericGenerator;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.PrePersist;
import javax.persistence.PreUpdate;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import java.time.LocalDateTime;

@Entity
@Data
@NoArgsConstructor
public class ToDo {

    @Id
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid")
    private String id;
    @NotNull
    @NotBlank
    private String description;

    @Column(insertable = true, updatable = false)
    private LocalDateTime created;
    private LocalDateTime modified;
    private boolean completed;

    public ToDo(String description){
        this.description = description;
    }

    @PrePersist
    void onCreate() {
        this.setCreated(LocalDateTime.now());
        this.setModified(LocalDateTime.now());
    }

    @PreUpdate
    void onUpdate() {
        this.setModified(LocalDateTime.now());
    }
}

package com.apress.todo.controller;

import com.apress.todo.domain.ToDo;
import com.apress.todo.domain.ToDoBuilder;
import com.apress.todo.repository.ToDoRepository;
import com.apress.todo.validation.ToDoValidationError;
import com.apress.todo.validation.ToDoValidationErrorBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.Errors;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;

import javax.validation.Valid;
import java.net.URI;
import java.util.Optional;

//@CrossOrigin(origins = "*", allowedHeaders = "*")
@RestController
@RequestMapping("/api")
public class ToDoController {
    private static Logger log = LoggerFactory.getLogger(ToDoController.class);
    private ToDoRepository toDoRepository;

    @Autowired
    public ToDoController(ToDoRepository toDoRepository) {
        this.toDoRepository = toDoRepository;
    }

    @GetMapping("/todo")
    public ResponseEntity<Iterable<ToDo>> getToDos(){
        return ResponseEntity.ok(toDoRepository.findAll());
    }

    @GetMapping("/todo/{id}")
    public ResponseEntity<ToDo> getToDoById(@PathVariable String id){
        Optional<ToDo> toDo =
                toDoRepository.findById(id);
        if(toDo.isPresent())
         return ResponseEntity.ok(toDo.get());

        return ResponseEntity.notFound().build();
    }

    @PatchMapping("/todo/{id}")
    public ResponseEntity<ToDo> setCompleted(@PathVariable String id){
        Optional<ToDo> toDo = toDoRepository.findById(id);
        if(!toDo.isPresent())
            return ResponseEntity.notFound().build();

        ToDo result = toDo.get();
        result.setCompleted(true);
        toDoRepository.save(result);

        URI location = ServletUriComponentsBuilder.fromCurrentRequest()
                .buildAndExpand(result.getId()).toUri();

        return ResponseEntity.ok().header("Location",location.toString()).build();
    }

    @RequestMapping(value="/todo", method = {RequestMethod.POST,RequestMethod.PUT})
    public ResponseEntity<?> createToDo(@Valid @RequestBody ToDo toDo, Errors errors){
        if (errors.hasErrors()) {
            errors.getAllErrors().stream().forEach(e -> log.error(e.getObjectName() + " " + e.getDefaultMessage()));
            return ResponseEntity.badRequest().body(ToDoValidationErrorBuilder.fromBindingErrors(errors));
        }

        ToDo result = toDoRepository.save(toDo);
        URI location = ServletUriComponentsBuilder.fromCurrentRequest().path("/{id}")
                .buildAndExpand(result.getId()).toUri();

        return ResponseEntity.created(location).body(result); //ResponseEntity.created(location).build();
    }

    @DeleteMapping("/todo/{id}")
    public ResponseEntity<ToDo> deleteToDo(@PathVariable String id){
        toDoRepository.delete(ToDoBuilder.create().withId(id).build());
        return ResponseEntity.noContent().build();
    }

    @DeleteMapping("/todo")
    public ResponseEntity<ToDo> deleteToDo(@RequestBody ToDo toDo){
        toDoRepository.delete(toDo);
        return ResponseEntity.noContent().build();
    }

    @ExceptionHandler
    @ResponseStatus(value = HttpStatus.BAD_REQUEST)
    public ToDoValidationError handleException(Exception exception) {
        log.error(exception.getMessage());
        return new ToDoValidationError(exception.getMessage());
    }

}