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如何进行基于构造函数或setter的依赖注入?

jdbctemplate spring-boot spring-mvc spring java

elec · 技术社区 · 9 年前

    public class Customer {
    private long id;
    private String firstName, lastName;


    public Customer(long id, String firstName, String lastName) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public String toString() {
        return String.format(
                "Customer[id=%d, firstName='%s', lastName='%s']",
                id, firstName, lastName);
    }
}

控制器:

@Controller
public class HelloController {

    @Autowired
    JdbcTemplate jdbcTemplate;


    Customer customer;


    @RequestMapping("/hello")
    public String hello(Model model, @RequestParam(value="name", required=false, defaultValue="World") String name) {
        model.addAttribute("name", name);
        return "hello";
    }

    @RequestMapping("/getMock")
    public String getMock(Model model) {

        JdbcTemplate mock = Mockito.mock(JdbcTemplate.class);

        List fakeList = new ArrayList<>();
        fakeList.add(new Customer(1l, "sth", "sth2"));



        Mockito.when(mock.query(any(String.class), any(RowMapper.class))).thenReturn(fakeList);

        List<Customer> mockResult = mock.query(
                "SELECT id, first_name, last_name FROM customers",
                (rs, rowNum) -> new Customer(rs.getLong("id"), rs.getString("first_name"), rs.getString("last_name"))
        );

        String result = null;
        for(Customer customer : mockResult) result += (customer.toString() + "<br>");

        model.addAttribute("mockString", result);
        return "hello";
    }

    @RequestMapping("/getDatabase")
    public String getDatabase(Model model) {
        List<Customer> list = jdbcTemplate.query(
                "SELECT id, first_name, last_name FROM customers",
                (rs, rowNum) -> new Customer(rs.getLong("id"), rs.getString("first_name"), rs.getString("last_name"))
        );

        String result = null;
        for (Customer customer : list) result += (customer.toString() + "<br>");
        model.addAttribute("databaseString", result);
        return "hello";
    }

2 回复 | 直到 9 年前

Hazim 9 年前

您可以按照以下代码段进行基于构造函数的依赖项注入:

JdbcTemplate jdbcTemplate;

@Autowired
public HelloController(JdbcTemplate jdbcTemplate){
    this.jdbcTemplate=jdbcTemplate;
}

或者您可以执行基于setter的依赖项注入,如下所示:

JdbcTemplate jdbcTemplate;

@Autowired
public void setJdbcTemplate(JdbcTemplate jdbcTemplate){
    this.jdbcTemplate=jdbcTemplate;
}

becem wniss 9 年前

首先,您应该添加 @component 注释,以便该类由spring管理。然后,要将客户属性注入控制器中,您需要

@Autowired Customer customer;

2) @Autowired public void setCustomer(Customer customer) { this.customer = customer; }

3) @Autowired public HelloController(Customer customer) { this.customer = customer; }