Fix [MDEP-931] Replace PrintWriter with Writer in AbstractSerializing Visitor and subclasses

src/main/java/org/apache/maven/plugins/dependency/tree/AbstractSerializingVisitor.java

@@ -18,7 +18,6 @@
  */
 package org.apache.maven.plugins.dependency.tree;
 
-import java.io.PrintWriter;
 import java.io.Writer;
 
 /**
@@ -31,7 +30,7 @@ public abstract class AbstractSerializingVisitor {
     /**
      * The writer to serialize to.
      */
-    protected final PrintWriter writer;
+    protected final Writer writer;
 
     /**
      * Constructor.
@@ -42,10 +41,6 @@ public abstract class AbstractSerializingVisitor {
      * @param writer the writer to serialize to.
      */
     public AbstractSerializingVisitor(Writer writer) {
-        if (writer instanceof PrintWriter) {
-            this.writer = (PrintWriter) writer;
-        } else {
-            this.writer = new PrintWriter(writer, true);
-        }
+        this.writer = writer;
     }
 }

src/main/java/org/apache/maven/plugins/dependency/tree/DOTDependencyNodeVisitor.java

@@ -18,6 +18,9 @@
  */
 package org.apache.maven.plugins.dependency.tree;
 
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.UncheckedIOException;
 import java.io.Writer;
 import java.util.List;
 
@@ -47,29 +50,45 @@ public DOTDependencyNodeVisitor(Writer writer) {
      */
     @Override
     public boolean visit(DependencyNode node) {
-        if (node.getParent() == null || node.getParent() == node) {
-            writer.write("digraph \"" + node.toNodeString() + "\" { " + System.lineSeparator());
-        }
+        try {
+            StringWriter stringWriter = new StringWriter();
+            if (node.getParent() == null || node.getParent() == node) {
+                writer.write("digraph \"" + node.toNodeString() + "\" { " + System.lineSeparator());
+            }
 
-        // Generate "currentNode -> Child" lines
+            // Generate "currentNode -> Child" lines
 
-        List<DependencyNode> children = node.getChildren();
+            List<DependencyNode> children = node.getChildren();
+            for (DependencyNode child : children) {
+                stringWriter.write("\t\"" + node.toNodeString() + "\" -> \"" + child.toNodeString() + "\" ;\n");
+            }
 
-        for (DependencyNode child : children) {
-            writer.println("\t\"" + node.toNodeString() + "\" -> \"" + child.toNodeString() + "\" ; ");
+            // Write the accumulated output to the provided writer
+            writer.write(stringWriter.toString());
+            writer.flush();
+            return true;
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to write to DOT output", e);
         }
-
-        return true;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean endVisit(DependencyNode node) {
-        if (node.getParent() == null || node.getParent() == node) {
-            writer.write(" } ");
+        try {
+            StringWriter stringWriter = new StringWriter();
+            if (node.getParent() == null || node.getParent() == node) {
+                stringWriter.write("}\n");
+            }
+
+            // Write the accumulated output to the provided writer
+            writer.write(stringWriter.toString());
+            writer.flush();
+            return true;
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to write to DOT output", e);
         }
-        return true;
     }
 }

src/main/java/org/apache/maven/plugins/dependency/tree/GraphmlDependencyNodeVisitor.java

@@ -18,6 +18,9 @@
  */
 package org.apache.maven.plugins.dependency.tree;
 
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.UncheckedIOException;
 import java.io.Writer;
 
 import org.apache.maven.shared.dependency.graph.DependencyNode;
@@ -63,37 +66,55 @@ public GraphmlDependencyNodeVisitor(Writer writer) {
      * {@inheritDoc}
      */
     @Override
-    public boolean endVisit(DependencyNode node) {
-        if (node.getParent() == null || node.getParent() == node) {
-            writer.write(GRAPHML_FOOTER);
-        } else {
-            DependencyNode p = node.getParent();
-            writer.print("<edge source=\"" + generateId(p) + "\" target=\"" + generateId(node) + "\">");
-            if (node.getArtifact().getScope() != null) {
-                // add Edge label
-                writer.print("<data key=\"d1\"><y:PolyLineEdge><y:EdgeLabel>"
-                        + node.getArtifact().getScope() + "</y:EdgeLabel></y:PolyLineEdge></data>");
+    public boolean visit(DependencyNode node) {
+        try {
+            StringWriter stringWriter = new StringWriter();
+            if (node.getParent() == null || node.getParent() == node) {
+                stringWriter.write(GRAPHML_HEADER);
             }
-            writer.println("</edge>");
+            // write node
+            stringWriter.write("<node id=\"" + generateId(node) + "\">");
+            // add node label
+            stringWriter.write("<data key=\"d0\"><y:ShapeNode><y:NodeLabel>" + node.toNodeString()
+                    + "</y:NodeLabel></y:ShapeNode></data>");
+            stringWriter.write("</node>\n");
+
+            // Write the accumulated output to the provided writer
+            writer.write(stringWriter.toString());
+            writer.flush();
+            return true;
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to write GraphML node", e);
         }
-        return true;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public boolean visit(DependencyNode node) {
-        if (node.getParent() == null || node.getParent() == node) {
-            writer.write(GRAPHML_HEADER);
+    public boolean endVisit(DependencyNode node) {
+        try {
+            StringWriter stringWriter = new StringWriter();
+            if (node.getParent() == null || node.getParent() == node) {
+                stringWriter.write(GRAPHML_FOOTER);
+            } else {
+                DependencyNode p = node.getParent();
+                stringWriter.write("<edge source=\"" + generateId(p) + "\" target=\"" + generateId(node) + "\">");
+                if (node.getArtifact().getScope() != null) {
+                    // add Edge label
+                    stringWriter.write("<data key=\"d1\"><y:PolyLineEdge><y:EdgeLabel>"
+                            + node.getArtifact().getScope() + "</y:EdgeLabel></y:PolyLineEdge></data>");
+                }
+                stringWriter.write("</edge>\n");
+            }
+
+            // Write the accumulated output to the provided writer
+            writer.write(stringWriter.toString());
+            writer.flush();
+            return true;
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to write GraphML edge or footer", e);
         }
-        // write node
-        writer.print("<node id=\"" + generateId(node) + "\">");
-        // add node label
-        writer.print("<data key=\"d0\"><y:ShapeNode><y:NodeLabel>" + node.toNodeString()
-                + "</y:NodeLabel></y:ShapeNode></data>");
-        writer.println("</node>");
-        return true;
     }
 
     /**

src/main/java/org/apache/maven/plugins/dependency/tree/JsonDependencyNodeVisitor.java

@@ -18,6 +18,8 @@
  */
 package org.apache.maven.plugins.dependency.tree;
 
+import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.io.Writer;
 import java.util.HashSet;
 import java.util.Set;
@@ -56,14 +58,20 @@ public boolean visit(DependencyNode node) {
      * @param node  the node to write
      */
     private void writeRootNode(DependencyNode node) {
-        Set<DependencyNode> visited = new HashSet<>();
-        int indent = 2;
-        StringBuilder sb = new StringBuilder();
-        sb.append("{").append("\n");
-        writeNode(indent, node, sb, visited);
-        sb.append("}").append("\n");
-        writer.write(sb.toString());
+        try {
+            StringBuilder sb = new StringBuilder();
+            Set<DependencyNode> visited = new HashSet<>();
+            int indent = 2;
+            sb.append("{").append("\n");
+            writeNode(indent, node, sb, visited);
+            sb.append("}").append("\n");
+            writer.write(sb.toString());
+            writer.flush();
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to write JSON output", e);
+        }
     }
+
     /**
      * Appends the node and its children to the string builder.
      *
@@ -83,6 +91,7 @@ private void writeNode(int indent, DependencyNode node, StringBuilder sb, Set<De
             writeChildren(indent, node, sb, visited);
         }
     }
+
     /**
      * Writes the children of the node to the string builder. And each children of each node will be written recursively.
      *
@@ -110,8 +119,16 @@ private void writeChildren(int indent, DependencyNode node, StringBuilder sb, Se
 
     @Override
     public boolean endVisit(DependencyNode node) {
-        return true;
+        try {
+            if (node.getParent() == null || node.getParent() == node) {
+                writer.flush();
+            }
+            return true;
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to flush JSON output", e);
+        }
     }
+
     /**
      * Appends the artifact values to the string builder.
      *
@@ -133,6 +150,7 @@ private void appendNodeValues(StringBuilder sb, int indent, Artifact artifact, b
             appendKeyWithoutComma(sb, indent, "optional", String.valueOf(artifact.isOptional()));
         }
     }
+
     /**
      * Appends a key value pair to the string builder.
      *
@@ -158,6 +176,7 @@ private void appendKeyValue(StringBuilder sb, int indent, String key, String val
                 .append(",")
                 .append("\n");
     }
+
     /**
      * Appends a key value pair to the string builder without a comma at the end. This is used for the last children of a node.
      *

src/main/java/org/apache/maven/plugins/dependency/tree/TGFDependencyNodeVisitor.java

@@ -18,6 +18,9 @@
  */
 package org.apache.maven.plugins.dependency.tree;
 
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.UncheckedIOException;
 import java.io.Writer;
 import java.util.ArrayList;
 import java.util.List;
@@ -35,7 +38,7 @@
 public class TGFDependencyNodeVisitor extends AbstractSerializingVisitor implements DependencyNodeVisitor {
 
     /**
-     * Utiity class to write an Edge.
+     * Utility class to write an Edge.
      *
      * @author <a href="mailto:[email protected]">Jerome Creignou</a>
      */
@@ -101,31 +104,50 @@ public TGFDependencyNodeVisitor(Writer writer) {
      * {@inheritDoc}
      */
     @Override
-    public boolean endVisit(DependencyNode node) {
-        if (node.getParent() == null || node.getParent() == node) {
-            // dump edges on last node endVisit
-            writer.println("#");
-            for (EdgeAppender edge : edges) {
-                writer.println(edge.toString());
-            }
-        } else {
-            DependencyNode p = node.getParent();
-            // using scope as edge label.
-            edges.add(new EdgeAppender(p, node, node.getArtifact().getScope()));
+    public boolean visit(DependencyNode node) {
+        try {
+            StringWriter stringWriter = new StringWriter();
+            // write node
+            stringWriter.write(generateId(node));
+            stringWriter.write(" ");
+            stringWriter.write(node.toNodeString());
+            stringWriter.write("\n");
+
+            // Write the accumulated output to the provided writer
+            writer.write(stringWriter.toString());
+            writer.flush();
+            return true;
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to write TGF node", e);
         }
-        return true;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public boolean visit(DependencyNode node) {
-        // write node
-        writer.write(generateId(node));
-        writer.write(" ");
-        writer.println(node.toNodeString());
-        return true;
+    public boolean endVisit(DependencyNode node) {
+        try {
+            StringWriter stringWriter = new StringWriter();
+            if (node.getParent() == null || node.getParent() == node) {
+                // dump edges on last node endVisit
+                stringWriter.write("#\n");
+                for (EdgeAppender edge : edges) {
+                    stringWriter.write(edge.toString());
+                }
+
+                // Write the accumulated output to the provided writer
+                writer.write(stringWriter.toString());
+                writer.flush();
+            } else {
+                DependencyNode parent = node.getParent();
+                // using scope as edge label.
+                edges.add(new EdgeAppender(parent, node, node.getArtifact().getScope()));
+            }
+            return true;
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to write TGF edges or footer", e);
+        }
     }
 
     /**