motan学习笔记 一 微博轻量级RPC框架Motan

SpanContext

Iterable<Map.Entry<String, String>> baggageItems();

Tracer

<C> void inject(SpanContext spanContext, Format<C> format, C carrier);
<C> SpanContext extract(Format<C> format, C carrier);

public interface Format<C> {final class Builtin<C> implements Format<C> { public final static Format<TextMap> TEXT_MAP = new Builtin<TextMap>();public final static Format<TextMap> HTTP_HEADERS = new Builtin<TextMap>();public final static Format<ByteBuffer> BINARY = new Builtin<ByteBuffer>();}

SpanBuilder

顾名思义，builder模式，用来构建 span, 关键是start方法，构建成功

interface SpanBuilder extends SpanContext {/*** A shorthand for addReference(References.CHILD_OF, parent).*/SpanBuilder asChildOf(SpanContext parent);/*** A shorthand for addReference(References.CHILD_OF, parent.context()).*/SpanBuilder asChildOf(Span parent);/*** Add a reference from the Span being built to a distinct (usually parent) Span. May be called multiple times to* represent multiple such References.** @param referenceType the reference type, typically one of the constants defined in References* @param referencedContext the SpanContext being referenced; e.g., for a References.CHILD_OF referenceType, the*                          referencedContext is the parent** @see io.opentracing.References*/SpanBuilder addReference(String referenceType, SpanContext referencedContext);/** Same as {@link Span#setTag(String, String)}, but for the span being built. */SpanBuilder withTag(String key, String value);/** Same as {@link Span#setTag(String, String)}, but for the span being built. */SpanBuilder withTag(String key, boolean value);/** Same as {@link Span#setTag(String, String)}, but for the span being built. */SpanBuilder withTag(String key, Number value);/** Specify a timestamp of when the Span was started, represented in microseconds since epoch. */SpanBuilder withStartTimestamp(long microseconds);/** Returns the started Span. */Span start();}