Handle i/o for SVG files better

schemacrawler-diagram/src/main/java/schemacrawler/tools/command/text/embeddeddiagram/EmbeddedDiagramRenderer.java

@@ -9,24 +9,20 @@
 package schemacrawler.tools.command.text.embeddeddiagram;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.nio.file.Files.deleteIfExists;
 import static java.nio.file.Files.newBufferedReader;
-import static java.nio.file.Files.newBufferedWriter;
-import static java.nio.file.StandardOpenOption.CREATE;
-import static java.nio.file.StandardOpenOption.TRUNCATE_EXISTING;
-import static java.nio.file.StandardOpenOption.WRITE;
 import static java.util.Objects.requireNonNull;
-import static schemacrawler.tools.command.text.diagram.options.DiagramOutputFormat.htmlx;
 import static schemacrawler.tools.command.text.diagram.options.DiagramOutputFormat.svg;
 import static schemacrawler.tools.command.text.schema.options.TextOutputFormat.html;
-import static us.fatehi.utility.IOUtility.copy;
-import static us.fatehi.utility.IOUtility.createTempFilePath;
 
 import java.io.BufferedReader;
 import java.io.BufferedWriter;
 import java.io.IOException;
 import java.io.UncheckedIOException;
-import java.io.Writer;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import java.util.regex.Pattern;
 import schemacrawler.schemacrawler.exceptions.ExecutionRuntimeException;
 import schemacrawler.schemacrawler.exceptions.SchemaCrawlerException;
@@ -43,31 +39,9 @@
 
 public class EmbeddedDiagramRenderer extends AbstractSchemaCrawlerCommand<DiagramOptions> {
 
+  private static final Logger LOGGER = Logger.getLogger(EmbeddedDiagramRenderer.class.getName());
+
   private static final Pattern svgInsertionPoint = Pattern.compile("<h2.*Tables.*h2>");
-  private static final Pattern svgStart = Pattern.compile("<svg.*");
-
-  private static void insertSvg(
-      final BufferedWriter finalHtmlFileWriter, final BufferedReader baseSvgFileReader)
-      throws IOException {
-    finalHtmlFileWriter.append(System.lineSeparator());
-    boolean skipLines = true;
-    boolean isSvgStart = false;
-    String line;
-    while ((line = baseSvgFileReader.readLine()) != null) {
-      if (skipLines) {
-        isSvgStart = svgStart.matcher(line).matches();
-        skipLines = !isSvgStart;
-      }
-      if (!skipLines) {
-        if (isSvgStart) {
-          line = "<svg";
-          isSvgStart = false;
-        }
-        finalHtmlFileWriter.append(line).append(System.lineSeparator());
-      }
-    }
-    finalHtmlFileWriter.append(System.lineSeparator());
-  }
 
   private final GraphExecutorFactory graphExecutorFactory;
 
@@ -83,31 +57,40 @@ public void execute() {
     checkCatalog();
 
     try {
-      final String stem = "schemacrawler";
-      final Path finalHtmlFile = createTempFilePath(stem, htmlx.getFormat());
-      final Path baseHtmlFile = createTempFilePath(stem, html.getFormat());
-      final Path baseSvgFile = createTempFilePath(stem, svg.getFormat());
-
-      final PropertyName commandName = getCommandName();
-      executeCommand(new SchemaTextRenderer(commandName), baseHtmlFile, html);
-      executeCommand(new DiagramRenderer(commandName, graphExecutorFactory), baseSvgFile, svg);
-
-      // Interleave HTML and SVG
-      try (final BufferedWriter finalHtmlFileWriter =
-              newBufferedWriter(finalHtmlFile, UTF_8, WRITE, CREATE, TRUNCATE_EXISTING);
-          final BufferedReader baseHtmlFileReader = newBufferedReader(baseHtmlFile, UTF_8);
-          final BufferedReader baseSvgFileReader = newBufferedReader(baseSvgFile, UTF_8)) {
-        String line;
-        while ((line = baseHtmlFileReader.readLine()) != null) {
-          if (svgInsertionPoint.matcher(line).matches()) {
-            insertSvg(finalHtmlFileWriter, baseSvgFileReader);
+      final Path tempDir = Files.createTempDirectory("schemacrawler");
+      final Path baseHtmlFile = tempDir.resolve("base." + html.getFormat());
+      final Path baseSvgFile = tempDir.resolve("base." + svg.getFormat());
+
+      try {
+        final PropertyName commandName = getCommandName();
+        executeCommand(new SchemaTextRenderer(commandName), baseHtmlFile, html);
+        executeCommand(new DiagramRenderer(commandName, graphExecutorFactory), baseSvgFile, svg);
+
+        // Interleave HTML and SVG, writing directly to the output writer
+        try (final BufferedWriter writer = new BufferedWriter(outputOptions.openNewOutputWriter());
+            final BufferedReader baseHtmlReader = newBufferedReader(baseHtmlFile, UTF_8)) {
+          final SVGInserter svgInserter = new SVGInserter(baseSvgFile);
+          boolean svgInserted = false;
+          String line;
+          while ((line = baseHtmlReader.readLine()) != null) {
+            if (!svgInserted && svgInsertionPoint.matcher(line).matches()) {
+              svgInserter.insert(writer);
+              svgInserted = true;
+            }
+            writer.append(line).append(System.lineSeparator());
+          }
+          if (!svgInserted) {
+            LOGGER.log(Level.WARNING, "SVG insertion point not found; embedded diagram is missing");
           }
-          finalHtmlFileWriter.append(line).append(System.lineSeparator());
         }
-      }
-
-      try (final Writer writer = outputOptions.openNewOutputWriter()) {
-        copy(newBufferedReader(finalHtmlFile, UTF_8), writer);
+      } finally {
+        try {
+          deleteIfExists(baseHtmlFile);
+          deleteIfExists(baseSvgFile);
+          deleteIfExists(tempDir);
+        } catch (final IOException e) {
+          LOGGER.log(Level.WARNING, "Could not delete temp files in " + tempDir, e);
+        }
       }
     } catch (final IOException e) {
       throw new UncheckedIOException("Could not create embedded diagram", e);

schemacrawler-diagram/src/main/java/schemacrawler/tools/command/text/embeddeddiagram/SVGInserter.java

@@ -0,0 +1,61 @@
+/*
+ * SchemaCrawler
+ * http://www.schemacrawler.com
+ * Copyright (c) 2000-2026, Sualeh Fatehi <sualeh@hotmail.com>.
+ * All rights reserved.
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+package schemacrawler.tools.command.text.embeddeddiagram;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Objects.requireNonNull;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.Writer;
+import java.nio.file.Path;
+import java.util.regex.Pattern;
+import us.fatehi.utility.ioresource.FileInputResource;
+
+class SVGInserter {
+
+  private enum SvgParseState {
+    PREAMBLE,
+    SVG_BODY
+  }
+
+  private static final Pattern svgStart = Pattern.compile("<svg.*");
+
+  private final FileInputResource svgResource;
+
+  SVGInserter(final Path svgFilePath) {
+    requireNonNull(svgFilePath, "No SVG file path provided");
+    svgResource = new FileInputResource(svgFilePath);
+  }
+
+  void insert(final Writer writer) throws IOException {
+    requireNonNull(writer, "No writer provided");
+    writer.write(System.lineSeparator());
+    SvgParseState state = SvgParseState.PREAMBLE;
+    try (final BufferedReader svgReader = svgResource.openNewInputReader(UTF_8)) {
+      String line;
+      while ((line = svgReader.readLine()) != null) {
+        switch (state) {
+          case PREAMBLE:
+            if (svgStart.matcher(line).find()) {
+              writer.write("<svg");
+              writer.write(System.lineSeparator());
+              state = SvgParseState.SVG_BODY;
+            }
+            break;
+          case SVG_BODY:
+            writer.write(line);
+            writer.write(System.lineSeparator());
+            break;
+        }
+      }
+    }
+    writer.write(System.lineSeparator());
+  }
+}