Feature : Allow setting custom linefeed on DefaultXmlPrettyPrinter

src/main/java/com/fasterxml/jackson/dataformat/xml/util/DefaultXmlPrettyPrinter.java

@@ -77,6 +77,27 @@ public interface Indenter
      */
     protected boolean _spacesInObjectEntries = true;
 
+    /**
+     * By default, will try to set as System.getProperty("line.separator").
+     * Can later set custom new line with withCustomNewLine method.
+     * @since 2.15
+     */
+    private static final String SYSTEM_DEFAULT_NEW_LINE;
+    static {
+        String lf = null;
+        try {
+            lf = System.getProperty("line.separator");
+        } catch (Exception t) { } // access exception?
+        SYSTEM_DEFAULT_NEW_LINE = lf;
+    }
+    protected String _newLine = SYSTEM_DEFAULT_NEW_LINE;
+
+    static final int SPACE_COUNT = 64;
+    static final char[] SPACES = new char[SPACE_COUNT];
+    static {
+        Arrays.fill(SPACES, ' ');
+    }
+
     /*
     /**********************************************************
     /* State
@@ -112,6 +133,7 @@ protected DefaultXmlPrettyPrinter(DefaultXmlPrettyPrinter base)
         _objectIndenter = base._objectIndenter;
         _spacesInObjectEntries = base._spacesInObjectEntries;
         _nesting = base._nesting;
+        _newLine = base._newLine;
     }
 
     public void indentArraysWith(Indenter i)
@@ -126,6 +148,15 @@ public void indentObjectsWith(Indenter i)
 
     public void spacesInObjectEntries(boolean b) { _spacesInObjectEntries = b; }
 
+    /**
+     * Sets custom new-line.
+     * @since 2.15
+     */
+    public DefaultXmlPrettyPrinter withCustomNewLine(String newLine) {
+        _newLine = newLine != null ? newLine : SYSTEM_DEFAULT_NEW_LINE;
+        return this;
+    }
+
     /*
     /**********************************************************
     /* Instantiatable impl
@@ -443,7 +474,7 @@ public void writeLeafXsiNilElement(XMLStreamWriter2 sw,
     public void writePrologLinefeed(XMLStreamWriter2 sw) throws XMLStreamException
     {
         // 06-Dec-2015, tatu: Alternatively could try calling `writeSpace()`...
-        sw.writeRaw(Lf2SpacesIndenter.SYSTEM_LINE_SEPARATOR);
+        sw.writeRaw(_newLine);
     }
 
     /*
@@ -486,7 +517,7 @@ public void writeIndentation(XMLStreamWriter2 sw, int level)
         {
             sw.writeRaw(" ");
         }
-        
+
         @Override
         public void writeIndentation(JsonGenerator g, int level) throws IOException
         {
@@ -501,26 +532,11 @@ public void writeIndentation(JsonGenerator g, int level) throws IOException
      * Default linefeed-based indenter uses system-specific linefeeds and
      * 2 spaces for indentation per level.
      */
-    protected static class Lf2SpacesIndenter
+    protected class Lf2SpacesIndenter
         implements Indenter, java.io.Serializable
     {
         private static final long serialVersionUID = 1L;
 
-        final static String SYSTEM_LINE_SEPARATOR;
-        static {
-            String lf = null;
-            try {
-                lf = System.getProperty("line.separator");
-            } catch (Throwable t) { } // access exception?
-            SYSTEM_LINE_SEPARATOR = (lf == null) ? "\n" : lf;
-        }
-
-        final static int SPACE_COUNT = 64;
-        final static char[] SPACES = new char[SPACE_COUNT];
-        static {
-            Arrays.fill(SPACES, ' ');
-        }
-
         public Lf2SpacesIndenter() { }
 
         @Override
@@ -529,7 +545,7 @@ public Lf2SpacesIndenter() { }
         @Override
         public void writeIndentation(XMLStreamWriter2 sw, int level) throws XMLStreamException
         {
-            sw.writeRaw(SYSTEM_LINE_SEPARATOR);
+            sw.writeRaw(_newLine);
             level += level; // 2 spaces per level
             while (level > SPACE_COUNT) { // should never happen but...
             	sw.writeRaw(SPACES, 0, SPACE_COUNT); 
@@ -541,7 +557,7 @@ public void writeIndentation(XMLStreamWriter2 sw, int level) throws XMLStreamExc
         @Override
         public void writeIndentation(JsonGenerator jg, int level) throws IOException
         {
-            jg.writeRaw(SYSTEM_LINE_SEPARATOR);
+            jg.writeRaw(_newLine);
             level += level; // 2 spaces per level
             while (level > SPACE_COUNT) { // should never happen but...
                 jg.writeRaw(SPACES, 0, SPACE_COUNT); 

src/test/java/com/fasterxml/jackson/dataformat/xml/ser/XmlPrettyPrinterTest.java

@@ -4,24 +4,26 @@
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+import com.fasterxml.jackson.core.PrettyPrinter;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.dataformat.xml.XmlMapper;
 import com.fasterxml.jackson.dataformat.xml.XmlTestBase;
 import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
 import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
+import com.fasterxml.jackson.dataformat.xml.util.DefaultXmlPrettyPrinter;
 
 public class XmlPrettyPrinterTest extends XmlTestBase
 {
     static class StringWrapperBean {
         public StringWrapper string;
-        
+
         public StringWrapperBean() { }
         public StringWrapperBean(String s) { string = new StringWrapper(s); }
     }
 
     static class IntWrapperBean {
         public IntWrapper wrapped;
-        
+
         public IntWrapperBean() { }
         public IntWrapperBean(int i) { wrapped = new IntWrapper(i); }
     }
@@ -44,11 +46,11 @@ public class PojoFor123
         @JacksonXmlProperty(isAttribute = true)
         public String name;
 
-        @JsonInclude(JsonInclude.Include.NON_EMPTY) 
+        @JsonInclude(JsonInclude.Include.NON_EMPTY)
         public String property;
 
         public PojoFor123(String name) {
-            this.name = name;       
+            this.name = name;
         }
     }
 
@@ -89,6 +91,8 @@ public void setUp() throws Exception {
         _xmlMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
     }
 
+    private static final String SYSTEM_DEFAULT_NEW_LINE = System.getProperty("line.separator");
+
     /*
     /**********************************************************
     /* Unit tests
@@ -176,16 +180,90 @@ public void testMultiLevel172() throws Exception
                 .writeValueAsString(root);
         // unify possible apostrophes to quotes
         xml = a2q(xml);
-        // with indentation, should get linefeeds in prolog/epilog too
-        assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
-                +"<Company>\n"
-                +"  <e>\n"
-                +"    <employee>\n"
-                +"      <id>abc</id>\n"
-                +"      <type>FULL_TIME</type>\n"
-                +"    </employee>\n"
-                +"  </e>\n"
-                +"</Company>\n",
+
+        assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + SYSTEM_DEFAULT_NEW_LINE
+                +"<Company>" + SYSTEM_DEFAULT_NEW_LINE
+                +"  <e>" + SYSTEM_DEFAULT_NEW_LINE
+                +"    <employee>" + SYSTEM_DEFAULT_NEW_LINE
+                +"      <id>abc</id>" + SYSTEM_DEFAULT_NEW_LINE
+                +"      <type>FULL_TIME</type>" + SYSTEM_DEFAULT_NEW_LINE
+                +"    </employee>" + SYSTEM_DEFAULT_NEW_LINE
+                +"  </e>" + SYSTEM_DEFAULT_NEW_LINE
+                +"</Company>" + SYSTEM_DEFAULT_NEW_LINE,
                 xml);
     }
+
+    public void testNewLine_withCustomNewLine() throws Exception {
+        String customNewLine = "\n\rLF\n\r";
+        PrettyPrinter customXmlPrettyPrinter = new DefaultXmlPrettyPrinter().withCustomNewLine(customNewLine);
+
+        Company root = new Company();
+        root.employee.add(new Employee("abc"));
+
+        String xml = _xmlMapper.writer()
+            .with(customXmlPrettyPrinter)
+            .with(ToXmlGenerator.Feature.WRITE_XML_DECLARATION)
+            .writeValueAsString(root);
+        // unify possible apostrophes to quotes
+        xml = a2q(xml);
+
+        // with indentation, should get newLines in prolog/epilog too
+        assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + customNewLine
+                + "<Company>" + customNewLine
+                + "  <e>" + customNewLine
+                + "    <employee>" + customNewLine
+                + "      <id>abc</id>" + customNewLine
+                + "      <type>FULL_TIME</type>" + customNewLine
+                + "    </employee>" + customNewLine
+                + "  </e>" + customNewLine
+                + "</Company>" + customNewLine,
+            xml);
+    }
+
+    public void testNewLine_systemDefault() throws Exception {
+        Company root = new Company();
+        root.employee.add(new Employee("abc"));
+
+        String xml = _xmlMapper.writer()
+            .with(new DefaultXmlPrettyPrinter())
+            .with(ToXmlGenerator.Feature.WRITE_XML_DECLARATION)
+            .writeValueAsString(root);
+        // unify possible apostrophes to quotes
+        xml = a2q(xml);
+
+        // with indentation, should get newLines in prolog/epilog too
+        assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + SYSTEM_DEFAULT_NEW_LINE
+                + "<Company>" + SYSTEM_DEFAULT_NEW_LINE
+                + "  <e>" + SYSTEM_DEFAULT_NEW_LINE
+                + "    <employee>" + SYSTEM_DEFAULT_NEW_LINE
+                + "      <id>abc</id>" + SYSTEM_DEFAULT_NEW_LINE
+                + "      <type>FULL_TIME</type>" + SYSTEM_DEFAULT_NEW_LINE
+                + "    </employee>" + SYSTEM_DEFAULT_NEW_LINE
+                + "  </e>" + SYSTEM_DEFAULT_NEW_LINE
+                + "</Company>" + SYSTEM_DEFAULT_NEW_LINE,
+            xml);
+    }
+
+    public void testNewLine_UseSystemDefaultLineSeperatorOnNullCustomNewLine() throws Exception {
+        Company root = new Company();
+        root.employee.add(new Employee("abc"));
+
+        String xml = _xmlMapper.writer()
+            .with(new DefaultXmlPrettyPrinter().withCustomNewLine(null))
+            .with(ToXmlGenerator.Feature.WRITE_XML_DECLARATION)
+            .writeValueAsString(root);
+        // unify possible apostrophes to quotes
+        xml = a2q(xml);
+
+        assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + SYSTEM_DEFAULT_NEW_LINE
+                + "<Company>" + SYSTEM_DEFAULT_NEW_LINE
+                + "  <e>" + SYSTEM_DEFAULT_NEW_LINE
+                + "    <employee>" + SYSTEM_DEFAULT_NEW_LINE
+                + "      <id>abc</id>" + SYSTEM_DEFAULT_NEW_LINE
+                + "      <type>FULL_TIME</type>" + SYSTEM_DEFAULT_NEW_LINE
+                + "    </employee>" + SYSTEM_DEFAULT_NEW_LINE
+                + "  </e>" + SYSTEM_DEFAULT_NEW_LINE
+                + "</Company>" + SYSTEM_DEFAULT_NEW_LINE,
+            xml);
+    }
 }