JDBC Blob columns are now output as Base64 instead of Object#toString(),

which usually is InputStream#toString()

Author: garydgregory

pom.xml

@@ -52,6 +52,11 @@
       <artifactId>commons-io</artifactId>
       <version>2.15.1</version>
     </dependency>
+    <dependency>
+      <groupId>commons-codec</groupId>
+      <artifactId>commons-codec</artifactId>
+      <version>1.16.1</version>
+    </dependency>
     <dependency>
       <groupId>org.apache.commons</groupId>
       <artifactId>commons-lang3</artifactId>

src/changes/changes.xml

@@ -52,6 +52,7 @@
       <action type="fix" issue="CSV-310" dev="ggregory" due-to="Buddhi De Silva">Misleading error message when QuoteMode set to None #352.</action>
       <action type="fix" issue="CSV-311" dev="ggregory" due-to="Christian Feuersaenger, Gary Gregory">OutOfMemory for very long rows despite using column value of type Reader.</action>
       <action type="fix" dev="ggregory" due-to="Gary Gregory">Use try-with-resources to manage JDBC Clob in CSVPrinter.printRecords(ResultSet).</action>
+      <action type="fix" dev="ggregory" due-to="Gary Gregory">JDBC Blob columns are now output as Base64 instead of Object#toString(), which usually is InputStream#toString().</action>
       <!-- UPDATE -->
       <action type="update" dev="ggregory" due-to="Gary Gregory">Bump commons-io:commons-io: from 2.11.0 to 2.15.1.</action>
       <action type="update" dev="ggregory" due-to="Gary Gregory, Dependabot">Bump commons-parent from 57 to 67.</action>

src/main/java/org/apache/commons/csv/CSVFormat.java

@@ -33,6 +33,8 @@
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Reader;
 import java.io.Serializable;
@@ -49,8 +51,11 @@
 import java.util.Objects;
 import java.util.Set;
 
+import org.apache.commons.codec.binary.Base64OutputStream;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.io.function.Uncheck;
+import org.apache.commons.io.output.AppendableOutputStream;
+import org.apache.commons.io.output.CloseShieldOutputStream;
 
 /**
  * Specifies the format of a CSV file for parsing and writing.
@@ -2030,6 +2035,9 @@ public synchronized void print(final Object value, final Appendable out, final b
         } else if (value instanceof Reader) {
             print((Reader) value, out, newRecord);
             return;
+        } else if (value instanceof InputStream) {
+            print((InputStream) value, out, newRecord);
+            return;
         } else {
             charSequence = value.toString();
         }
@@ -2074,8 +2082,28 @@ public CSVPrinter print(final Path out, final Charset charset) throws IOExceptio
         return print(Files.newBufferedWriter(out, charset));
     }
 
+    private void print(final InputStream inputStream, final Appendable out, final boolean newRecord) throws IOException {
+        // InputStream is never null here
+        // There is nothing to escape when quoting is used which is the default.
+        if (!newRecord) {
+            append(getDelimiterString(), out);
+        }
+        final boolean quoteCharacterSet = isQuoteCharacterSet();
+        if (quoteCharacterSet) {
+            append(getQuoteCharacter().charValue(), out);
+        }
+        // Stream the input to the output without reading or holding the whole value in memory. 
+        // AppendableOutputStream cannot "close" an Appendable.
+        try (OutputStream outputStream = new Base64OutputStream(new AppendableOutputStream<>(out))) {
+            IOUtils.copy(inputStream, outputStream);
+        }
+        if (quoteCharacterSet) {
+            append(getQuoteCharacter().charValue(), out);
+        }
+    }
+
     private void print(final Reader reader, final Appendable out, final boolean newRecord) throws IOException {
-        // Reader is never null
+        // Reader is never null here
         if (!newRecord) {
             append(getDelimiterString(), out);
         }
@@ -2088,7 +2116,6 @@ private void print(final Reader reader, final Appendable out, final boolean newR
         } else {
             IOUtils.copy(reader, out);
         }
-
     }
 
     /**

src/main/java/org/apache/commons/csv/CSVPrinter.java

@@ -24,7 +24,9 @@
 import java.io.Closeable;
 import java.io.Flushable;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.Reader;
+import java.sql.Blob;
 import java.sql.Clob;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -419,6 +421,10 @@ public void printRecords(final ResultSet resultSet) throws SQLException, IOExcep
                     try (Reader reader = ((Clob) object).getCharacterStream()) {
                         print(reader);
                     }
+                } else if (object instanceof Blob) {
+                    try (InputStream inputStream = ((Blob) object).getBinaryStream()) {
+                        print(inputStream);
+                    }
                 } else {
                     print(object);
                 }