在Spring Boot的构造函数中是否强制使用@Autowired批注 [英] Is @Autowired annotation mandatory on constructor in Spring boot

问题描述

如果我使用构造函数DI，是否必须放置@Autowired?

Is it mandatory to put @Autowired if I am using constructor DI?

推荐答案

@Autowired注释对构造函数是强制性的吗?

Is @Autowired annotation mandatory for a constructor?

否

在 Spring 4.3 如果您的类只有单个构造函数，则无需放置@Autowired.

After Spring 4.3 If your class has only single constructor then there is no need to put @Autowired.

在Spring 4.3之前:

package com.example.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class DatabaseAccountService implements AccountService {

    private final RiskAssessor riskAssessor;

    @Autowired
    public DatabaseAccountService(RiskAssessor riskAssessor) {
        this.riskAssessor = riskAssessor;
    }

    // ...

}

之后:

@Service
public class DatabaseAccountService implements AccountService {

    private final RiskAssessor riskAssessor;

    public DatabaseAccountService(RiskAssessor riskAssessor) {
        this.riskAssessor = riskAssessor;
    }

    // ...

}

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