Preparation work for RIOT RDF/XML parsers

jena-arq/src/main/java/org/apache/jena/riot/system/PrintingStreamRDF.java

@@ -20,17 +20,20 @@
 
 import java.io.OutputStream ;
 
+import org.apache.jena.atlas.io.AWriter;
 import org.apache.jena.atlas.io.IO;
+import org.apache.jena.graph.Triple;
 import org.apache.jena.riot.out.NodeFormatter;
 import org.apache.jena.riot.out.NodeFormatterTTL;
 import org.apache.jena.riot.writer.WriterStreamRDFPlain;
+import org.apache.jena.sparql.core.Quad;
 
 /**
- * A StreamRDF which displays the items sent to the stream. It is primarily for
- * development purposes.
+ * A StreamRDF which displays the items sent to the stream.
+ * It is primarily for development purposes.
  * <p>
  * The output is not a legal syntax. Do not consider this
- * format to be stable. It is "N-Quads with abbreviations".
+ * format to be stable.
  * <p>
  * Use via
  * <pre>
@@ -44,17 +47,33 @@ public class PrintingStreamRDF extends WriterStreamRDFPlain
 
     public PrintingStreamRDF(OutputStream out) {
         super(IO.wrapUTF8(out));
+        // Always flush on each items.
+        // Too many points provide buffering or automatic newline
+        // handling  in different ways to get implicit consistent behaviour.
+        // This is a development helper.
+    }
+
+    public PrintingStreamRDF(AWriter out) {
+        super(out);
     }
 
     @Override
     protected NodeFormatter getFmt() { return pretty; }
 
+    // No prefix formatting.
+    private static void printDirectURI(AWriter out, String iriStr) {
+        out.print("<") ;
+        out.print(iriStr) ;
+        out.print(">") ;
+    }
+
     @Override
     public void base(String base) {
         out.print("BASE") ;
-        out.print("    ") ;
-        getFmt().formatURI(out, base);
+        out.print("  ") ;
+        printDirectURI(out, base);
         out.println();
+        flush();
         // Reset the formatter because of the new base URI.
         pretty = new NodeFormatterTTL(base, prefixMap);
     }
@@ -65,8 +84,25 @@ public void prefix(String prefix, String iri) {
         out.print("  ") ;
         out.print(prefix) ;
         out.print(":  ") ;
-        getFmt().formatURI(out, iri);
+        printDirectURI(out, iri);
         out.println();
         prefixMap.add(prefix, iri);
+        flush();
+    }
+
+    @Override
+    public void triple(Triple triple) {
+        super.triple(triple);
+        flush();
+    }
+
+    @Override
+    public void quad(Quad quad) {
+        super.quad(quad);
+        flush();
+    }
+
+    public void flush() {
+        IO.flush(out) ;
     }
 }

jena-arq/src/main/java/org/apache/jena/riot/system/RiotLib.java

@@ -22,7 +22,6 @@
 import static org.apache.jena.riot.RDFLanguages.NTRIPLES;
 import static org.apache.jena.riot.RDFLanguages.RDFJSON;
 import static org.apache.jena.riot.RDFLanguages.sameLang;
-import static org.apache.jena.riot.writer.WriterConst.PREFIX_IRI;
 
 import java.io.OutputStream;
 import java.io.Writer;
@@ -296,7 +295,7 @@ public static void writeBase(IndentedWriter out, String base, boolean newStyle)
     private static void writeBaseNewStyle(IndentedWriter out, String base) {
         if (base != null) {
             out.print("BASE ");
-            out.pad(PREFIX_IRI);
+            out.pad(7);   // Align to possible prefixes. 7 is the length of "prefix "
             out.print("<");
             out.print(base);
             out.print(">");
@@ -307,7 +306,7 @@ private static void writeBaseNewStyle(IndentedWriter out, String base) {
     private static void writeBaseOldStyle(IndentedWriter out, String base) {
         if (base != null) {
             out.print("@base ");
-            out.pad(PREFIX_IRI);
+            out.pad(8);   // Align to possible prefixes. 8 is the length of "@prefix "
             out.print("<");
             out.print(base);
             out.print(">");
@@ -348,11 +347,11 @@ public static void writePrefix(IndentedWriter out, String prefix, String uri, bo
         writePrefix(out, prefix, uri, newStyle, 0);
     }
 
-    private static void writePrefix(IndentedWriter out, String prefix, String uri, boolean newStyle, int maxPrefixLenght) {
+    private static void writePrefix(IndentedWriter out, String prefix, String uri, boolean newStyle, int maxPrefixLength) {
         if (newStyle)
-            writePrefixNewStyle(out, prefix, uri, maxPrefixLenght);
+            writePrefixNewStyle(out, prefix, uri, maxPrefixLength);
         else
-            writePrefixOldStyle(out, prefix, uri, maxPrefixLenght);
+            writePrefixOldStyle(out, prefix, uri, maxPrefixLength);
     }
 
     /**
@@ -362,7 +361,7 @@ private static void writePrefixNewStyle(IndentedWriter out, String prefix, Strin
         out.print("PREFIX ");
         out.print(prefix);
         out.print(": ");
-        out.pad(9 + intent); // 9 e.q. length of "PREFIX" plus ": "
+        out.pad(9 + intent); // 9 is length of "PREFIX : "
         out.print("<");
         out.print(uri);
         out.print(">");
@@ -376,7 +375,7 @@ private static void writePrefixOldStyle(IndentedWriter out, String prefix, Strin
         out.print("@prefix ");
         out.print(prefix);
         out.print(": ");
-        out.pad(10 + intent); // 10 e.q. length of "@prefix" plus ": "
+        out.pad(10 + intent); // 10 is length of "@prefix : "
         out.print("<");
         out.print(uri);
         out.print(">");

jena-arq/src/main/java/org/apache/jena/riot/system/StreamRDFLib.java

@@ -46,6 +46,12 @@ public class StreamRDFLib
      */
     public static StreamRDF print(OutputStream out)         { return new PrintingStreamRDF(out); }
 
+    /**
+     * Create a {@link StreamRDF} that prints to an {@link AWriter}.
+     * This is debug output.
+     */
+    public static StreamRDF print(AWriter out)              { return new PrintingStreamRDF(out); }
+
     /**
      * Create a {@link StreamRDF} that outputs to an {@link OutputStream}. It is important
      * to call {@link StreamRDF#start} and {@link StreamRDF#finish} because the output is

jena-base/src/main/java/org/apache/jena/atlas/io/IndentedLineBuffer.java

@@ -20,7 +20,7 @@
 
 import java.io.StringWriter ;
 
-/** IndentLineBuffer is a buffer that records an indent level 
+/** IndentLineBuffer is a buffer that records an indent level
  *  and uses that to insert a prefix at each line.
  *  It can also insert line numbers at the beginning of lines.
  */
@@ -29,22 +29,22 @@ public class IndentedLineBuffer extends IndentedWriter
 {
     StringWriter sw ;
     public IndentedLineBuffer() { this(false) ; }
-    
+
     public IndentedLineBuffer(boolean withLineNumbers)
     {
         super(new StringWriter(), withLineNumbers) ;
         sw = (StringWriter)super.out ;
     }
-    
+
     public StringBuffer getBuffer() { return sw.getBuffer(); }
-    
+
     public String asString() { return sw.toString() ; }
     @Override
     public String toString() { return asString() ; }
 
     // Names more usually used for a buffer.
     public void append(String fmt, Object... args) { printf(fmt, args) ; }
     public void append(char ch)  { print(ch) ;}
-    
+
     public void clear() { sw.getBuffer().setLength(0) ; }
 }