[英]Replacing ImmutableMap keys in AutoValue with toBuilder()
I've come across a problem when using AutoValue with geneated Builder and fields with Guava ImmutableMap.将 AutoValue 与生成的 Builder 和带有 Guava ImmutableMap 的字段一起使用时,我遇到了一个问题。
Say we have this Container value class:假设我们有这个 Container 值 class:
public abstract class Container {
public abstract ImmutableMap<String, String> metadata();
public abstract Builder toBuilder();
public static Builder builder() {
return new AutoValue_Container.Builder();
}
@AutoValue.Builder
public abstract static class Builder {
public abstract ImmutableMap.Builder<String, String> metadataBuilder();
public final Builder addMetadata(String key, String value) {
metadataBuilder().put(key, value);
return this;
}
}
}
When I want to do the following, the ImmutableMap builder throws java.lang.IllegalArgumentException: Multiple entries with same key
当我想要执行以下操作时,ImmutableMap 构建器会抛出
java.lang.IllegalArgumentException: Multiple entries with same key
aContainer.toBuilder().addMetadata("existingKey", "someNewValue");
Does anyone familiar with AutoValue know how to coax the implementation to do as told?是否有熟悉 AutoValue 的人知道如何哄骗实现按要求执行?
There's a documented workaround in the builders-howto documentation . builders-howto 文档中有一个记录在案的解决方法。 Quote:
引用:
@AutoValue
public abstract class Foo {
public abstract ImmutableMap<Integer, String> map();
...
@AutoValue.Builder
public abstract static class Builder {
private final ImmutableMap.Builder<Integer, String> mapBuilder = ImmutableMap.builder();
public ImmutableMap.Builder<Integer, String> mapBuilder() {
return mapBuilder;
}
abstract Builder setMap(ImmutableMap<Integer, String> map); // not public
abstract Foo autoBuild(); // not public
public Foo build() {
setMap(mapBuilder.buildKeepingLast());
return autoBuild();
}
...
// #start
// Needed only if your class has toBuilder() method
public Builder toBuilder() {
Builder builder = autoToBuilder();
builder.mapBuilder().putAll(map());
return builder;
}
abstract Builder autoToBuilder(); // not public
// #end
}
}
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