Fix "expected label name, got \"BCLOSE\"" error

Author: wangkaish

simpleclient_common/src/main/java/io/prometheus/client/exporter/common/TextFormat.java

@@ -1,11 +1,11 @@
 package io.prometheus.client.exporter.common;
 
 import java.io.IOException;
-import java.io.StringWriter;
 import java.io.Writer;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Enumeration;
+import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 
@@ -22,7 +22,8 @@ public class TextFormat {
    *
    * @since 0.10.0
    */
-  public final static String CONTENT_TYPE_OPENMETRICS_100 = "application/openmetrics-text; version=1.0.0; charset=utf-8";
+  public final static String CONTENT_TYPE_OPENMETRICS_100 =
+          "application/openmetrics-text; version=1.0.0; charset=utf-8";
 
   /**
    * Return the content type that should be used for a given Accept HTTP header.
@@ -48,14 +49,15 @@ public static String chooseContentType(String acceptHeader) {
    *
    * @since 0.10.0
    */
-  public static void writeFormat(String contentType, Writer writer, Enumeration<Collector.MetricFamilySamples> mfs) throws IOException {
+  public static void writeFormat(
+          String contentType, Writer writer, Enumeration<Collector.MetricFamilySamples> mfs) throws IOException {
     if (CONTENT_TYPE_004.equals(contentType)) {
-        write004(writer, mfs);
-        return;
+      write004(writer, mfs);
+      return;
     }
     if (CONTENT_TYPE_OPENMETRICS_100.equals(contentType)) {
-        writeOpenMetrics100(writer, mfs);
-        return;
+      writeOpenMetrics100(writer, mfs);
+      return;
     }
     throw new IllegalArgumentException("Unknown contentType " + contentType);
   }
@@ -67,7 +69,7 @@ public static void write004(Writer writer, Enumeration<Collector.MetricFamilySam
     Map<String, Collector.MetricFamilySamples> omFamilies = new TreeMap<String, Collector.MetricFamilySamples>();
     /* See http://prometheus.io/docs/instrumenting/exposition_formats/
      * for the output format specification. */
-    while(mfs.hasMoreElements()) {
+    while (mfs.hasMoreElements()) {
       Collector.MetricFamilySamples metricFamilySamples = mfs.nextElement();
       String name = metricFamilySamples.name;
       writer.write("# HELP ");
@@ -97,33 +99,23 @@ public static void write004(Writer writer, Enumeration<Collector.MetricFamilySam
       String createdName = name + "_created";
       String gcountName = name + "_gcount";
       String gsumName = name + "_gsum";
-      for (Collector.MetricFamilySamples.Sample sample: metricFamilySamples.samples) {
+      for (Collector.MetricFamilySamples.Sample sample : metricFamilySamples.samples) {
         /* OpenMetrics specific sample, put in a gauge at the end. */
         if (sample.name.equals(createdName)
-            || sample.name.equals(gcountName)
-            || sample.name.equals(gsumName)) {
+                || sample.name.equals(gcountName)
+                || sample.name.equals(gsumName)) {
           Collector.MetricFamilySamples omFamily = omFamilies.get(sample.name);
           if (omFamily == null) {
-            omFamily = new Collector.MetricFamilySamples(sample.name, Collector.Type.GAUGE, metricFamilySamples.help, new ArrayList<Collector.MetricFamilySamples.Sample>());
+            omFamily = new Collector.MetricFamilySamples(sample.name,
+                    Collector.Type.GAUGE, metricFamilySamples.help,
+                    new ArrayList<Collector.MetricFamilySamples.Sample>());
             omFamilies.put(sample.name, omFamily);
           }
           omFamily.samples.add(sample);
           continue;
         }
-        writer.write(sample.name);
-        if (sample.labelNames.size() > 0) {
-          writer.write('{');
-          for (int i = 0; i < sample.labelNames.size(); ++i) {
-            writer.write(sample.labelNames.get(i));
-            writer.write("=\"");
-            writeEscapedLabelValue(writer, sample.labelValues.get(i));
-            writer.write("\",");
-          }
-          writer.write('}');
-        }
-        writer.write(' ');
-        writer.write(Collector.doubleToGoString(sample.value));
-        if (sample.timestampMs != null){
+        appendSamples(writer, sample);
+        if (sample.timestampMs != null) {
           writer.write(' ');
           writer.write(sample.timestampMs.toString());
         }
@@ -136,6 +128,30 @@ public static void write004(Writer writer, Enumeration<Collector.MetricFamilySam
     }
   }
 
+  private static void appendSamples(Writer writer, Collector.MetricFamilySamples.Sample sample) throws IOException {
+    writer.write(sample.name);
+    List<String> labelNames = sample.labelNames;
+    List<String> labelValues = sample.labelValues;
+    int sampleSize = labelNames.size();
+    if (sampleSize > 0) {
+      writer.write('{');
+      writer.write(labelNames.get(0));
+      writer.write("=\"");
+      writeEscapedLabelValue(writer, labelValues.get(0));
+      writer.write("\"");
+      for (int i = 1; i < sampleSize; ++i) {
+        writer.write(",");
+        writer.write(labelNames.get(i));
+        writer.write("=\"");
+        writeEscapedLabelValue(writer, labelValues.get(i));
+        writer.write("\"");
+      }
+      writer.write('}');
+    }
+    writer.write(' ');
+    writer.write(Collector.doubleToGoString(sample.value));
+  }
+
   private static void writeEscapedHelp(Writer writer, String s) throws IOException {
     for (int i = 0; i < s.length(); i++) {
       char c = s.charAt(i);
@@ -197,8 +213,9 @@ private static String typeString(Collector.Type t) {
    *
    * @since 0.10.0
    */
-  public static void writeOpenMetrics100(Writer writer, Enumeration<Collector.MetricFamilySamples> mfs) throws IOException {
-    while(mfs.hasMoreElements()) {
+  public static void writeOpenMetrics100(
+          Writer writer, Enumeration<Collector.MetricFamilySamples> mfs) throws IOException {
+    while (mfs.hasMoreElements()) {
       Collector.MetricFamilySamples metricFamilySamples = mfs.nextElement();
       String name = metricFamilySamples.name;
 
@@ -221,31 +238,16 @@ public static void writeOpenMetrics100(Writer writer, Enumeration<Collector.Metr
       writer.write(' ');
       writeEscapedLabelValue(writer, metricFamilySamples.help);
       writer.write('\n');
- 
-      for (Collector.MetricFamilySamples.Sample sample: metricFamilySamples.samples) {
-        writer.write(sample.name);
-        if (sample.labelNames.size() > 0) {
-          writer.write('{');
-          for (int i = 0; i < sample.labelNames.size(); ++i) {
-            if (i > 0) {
-              writer.write(",");
-            }
-            writer.write(sample.labelNames.get(i));
-            writer.write("=\"");
-            writeEscapedLabelValue(writer, sample.labelValues.get(i));
-            writer.write("\"");
-          }
-          writer.write('}');
-        }
-        writer.write(' ');
-        writer.write(Collector.doubleToGoString(sample.value));
-        if (sample.timestampMs != null){
+
+      for (Collector.MetricFamilySamples.Sample sample : metricFamilySamples.samples) {
+        appendSamples(writer, sample);
+        if (sample.timestampMs != null) {
           writer.write(' ');
           omWriteTimestamp(writer, sample.timestampMs);
         }
         if (sample.exemplar != null) {
           writer.write(" # {");
-          for (int i=0; i<sample.exemplar.getNumberOfLabels(); i++) {
+          for (int i = 0; i < sample.exemplar.getNumberOfLabels(); i++) {
             if (i > 0) {
               writer.write(",");
             }