java - Spring 将单例 bean 注入(inject)原型(prototype) bean 导致单例重新创建

Question

我目前有一个简单的 singleton bean 作为 pojo，我将其注入(inject)到工作线程中，该线程是用 @scope("prototype") 定义的。

我发现singleton bean被正确注入(inject)到原型(prototype)中，singleton正在被重新初始化并且所有值都返回null .

这是注入(inject)单例的代码:

@Component("filterWorkerPaired")
@Scope("prototype")
public class FilteringWorkerPaired implements FilteringWorker {


private RangeFilteringParams rangeFilteringParams;


@Inject
@Named("rangeFilteringParams")
public void setRangeFilteringParams(RangeFilteringParams rangeFilteringParams) {
    this.rangeFilteringParams = rangeFilteringParams;
}

波乔:

@Component("rangeFilteringParams")
public class RangeFilteringParams {

private Footprint footprint;
private SpanLength spanLength;
private WindowLength windowLength;
private boolean isPaired;
private List<MappingStrandSE> mappingStrandsSE;
private List<MappingTypeSE> mappingTypesSE;
private List<MappingStrandPE> mappingStrandsPE;
private List<MappingTypePE> mappingTypesPE;
private String suffix;
private boolean isLastStream = false; //default

@PostConstruct
public void init(){
    System.out.println("init filtering ");
}

@PreDestroy
public void destory(){
    System.out.println("destoryed");
}

public boolean isLastStream() {
    return isLastStream;
}

public void setLastStream(boolean lastStream) {
    isLastStream = lastStream;
}

public Footprint getFootprint() {
    return footprint;
}

public void setFootprint(Footprint footprint) {
    this.footprint = footprint;
}

public String getSuffix() {
    return suffix;
}

public void setSuffix(String suffix) {
    this.suffix = suffix;
}

public SpanLength getSpanLength() {
    return spanLength;
}

public void setSpanLength(SpanLength spanLength) {
    this.spanLength = spanLength;
}

public WindowLength getWindowLength() {
    return windowLength;
}

public void setWindowLength(WindowLength windowLength) {
    this.windowLength = windowLength;
}

public boolean isPaired() {
    return isPaired;
}

public void setPaired(boolean paired) {
    isPaired = paired;
}

public List<MappingStrandSE> getMappingStrandsSE() {
    return mappingStrandsSE;
}

public void setMappingStrandsSE(List<MappingStrandSE> mappingStrandsSE) {
    this.mappingStrandsSE = mappingStrandsSE;
}

public List<MappingTypeSE> getMappingTypesSE() {
    return mappingTypesSE;
}

public void setMappingTypesSE(List<MappingTypeSE> mappingTypesSE) {
    this.mappingTypesSE = mappingTypesSE;
}

public List<MappingStrandPE> getMappingStrandsPE() {
    return mappingStrandsPE;
}

public void setMappingStrandsPE(List<MappingStrandPE> mappingStrandsPE) {
    this.mappingStrandsPE = mappingStrandsPE;
}

public List<MappingTypePE> getMappingTypesPE() {
    return mappingTypesPE;
}

public void setMappingTypesPE(List<MappingTypePE> mappingTypesPE) {
    this.mappingTypesPE = mappingTypesPE;
}

}

我知道 RangeFileringParams bean 正在重新创建，因为 ID 在调试器中发生更改，并且 init 过滤 被打印到控制台。

以这种方式将单例注入(inject)原型(prototype)有什么问题吗？

谢谢。

Answer 1

正如你所说，问题已解决，但无论如何。如果您要创建具有初始状态的 bean，我建议使用配置而不是仅使用 @Component 注释，然后您可以创建 bean 并在一处初始化字段。例如:

@Configuration
public class RangeFilteringParamsConfiguration {

    @Bean
    public RangeFilteringParams rangeFilteringParams() {
        RangeFilteringParams params = new RangeFilteringParams();
        //set the fields here...
        return params;
    }
}