Checking for null object values, tiny refactoring.

mjfryc · Sep 7, 2021 · bb0ad2f · bb0ad2f
1 parent 631908d
commit bb0ad2f
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Showing 10 changed files with 264 additions and 24 deletions.
diff --git a/build.gradle b/build.gradle
@@ -17,6 +17,8 @@
  * OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
+import java.io.File
+
 plugins {
     id 'java'
     id 'maven-publish'
@@ -31,7 +33,7 @@ def detectVersionTag() {
         def allTags = new String(procAllTags.getInputStream().readAllBytes())
 
         def allTagsByLine = allTags.split('\n')
-        for (int i = allTagsByLine.size() -1; i >= 0; --i) {
+        for (int i = allTagsByLine.size() - 1; i >= 0; --i) {
             def iLine = allTagsByLine[i] as String
             def iTrimmedLine = iLine.trim()
             if (!iTrimmedLine.isEmpty()) {
@@ -65,7 +67,7 @@ def detectVersionTag() {
 }
 
 group 'pl.mjaron'
-version "0.1.1"
+version "0.1.2"
 println("Project version determined: $version")
 
 java {

diff --git a/src/main/java/pl/mjaron/etudes/Str.java b/src/main/java/pl/mjaron/etudes/Str.java
@@ -25,6 +25,29 @@
  * String utilities class.
  */
 public abstract class Str {
+
+    /**
+     * @param what Any nullable String.
+     * @return String object given in parameter or empty String it
+     */
+    public static String orEmpty(final String what) {
+        if (what == null) {
+            return "";
+        }
+        return what;
+    }
+
+    /**
+     * @param what Any object.
+     * @return toString() result or empty String if given object was null.
+     */
+    public static String orEmpty(final Object what) {
+        if (what == null) {
+            return "";
+        }
+        return what.toString();
+    }
+
     /**
      * @param what String where looking for char occurrences.
      * @param ch   Searched character.

diff --git a/src/main/java/pl/mjaron/etudes/flat/BeanTableSource.java b/src/main/java/pl/mjaron/etudes/flat/BeanTableSource.java
@@ -20,6 +20,7 @@
 package pl.mjaron.etudes.flat;
 
 import pl.mjaron.etudes.Obj;
+import pl.mjaron.etudes.Str;
 
 import java.lang.reflect.Field;
 import java.util.ArrayList;
@@ -45,11 +46,6 @@ public BeanTableSource(final Iterable<BeanT> values, final Class<BeanT> tClass)
         this.headers = Obj.getFieldNames(this.tClass, tFields);
     }
 
-    @Override
-    public boolean hasHeaders() {
-        return true;
-    }
-
     @Override
     public int getColumnsCount() {
         return tFields.length;
@@ -89,7 +85,7 @@ public Iterable<String> next() {
             Obj.visitFieldValues(bean, this.tClass, this.tFields, new Obj.IFieldVisitor() {
                 @Override
                 public void visit(final String name, final Object value) {
-                    stringSeries.add(value.toString());
+                    stringSeries.add(Str.orEmpty(value));
                 }
             });
             return stringSeries;

diff --git a/src/main/java/pl/mjaron/etudes/flat/ITableSource.java b/src/main/java/pl/mjaron/etudes/flat/ITableSource.java
@@ -26,8 +26,9 @@
  */
 public interface ITableSource extends Iterable<Iterable<String>> {
 
-    boolean hasHeaders();
-
+    /**
+     * @return Width of table.
+     */
     int getColumnsCount();
 
     /**
@@ -41,6 +42,10 @@ public interface ITableSource extends Iterable<Iterable<String>> {
     @Override
     Iterator<Iterable<String>> iterator();
 
+    default boolean hasHeaders() {
+        return getHeaders() != null;
+    }
+
     default void readTo(final ITableWriter writer) {
         ITableWriter.writeOperation(this, writer);
     }

diff --git a/src/main/java/pl/mjaron/etudes/flat/ListTableSource.java b/src/main/java/pl/mjaron/etudes/flat/ListTableSource.java
@@ -19,10 +19,10 @@
 
 package pl.mjaron.etudes.flat;
 
-import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
+@Deprecated
 public class ListTableSource<T> implements ITableSource {
 
     final List<List<T>> array;
@@ -31,11 +31,6 @@ public ListTableSource(final List<List<T>> array) {
         this.array = array;
     }
 
-    @Override
-    public boolean hasHeaders() {
-        return false;
-    }
-
     @Override
     public int getColumnsCount() {
         if (array.size() == 0) return 0;
@@ -44,10 +39,7 @@ public int getColumnsCount() {
 
     @Override
     public Iterable<String> getHeaders() {
-        if (array.size() == 0) {
-            return new ArrayList<>();
-        }
-        return StringSeries.from(array.get(0));
+        return null;
     }
 
     @Override

diff --git a/src/main/java/pl/mjaron/etudes/flat/SeriesIteratorFactory.java b/src/main/java/pl/mjaron/etudes/flat/SeriesIteratorFactory.java
@@ -0,0 +1,157 @@
+/*
+ * Copyright  2021  Michał Jaroń <m.jaron@protonmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the
+ * following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies
+ * or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+ * KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+ * OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package pl.mjaron.etudes.flat;
+
+import java.util.Iterator;
+
+public abstract class SeriesIteratorFactory {
+
+    private SeriesIteratorFactory() {
+    }
+
+    public static Iterator<String> from(final byte[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+    public static Iterator<String> from(final short[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+    public static Iterator<String> from(final int[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+    public static Iterator<String> from(final long[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+    public static Iterator<String> from(final float[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+    public static Iterator<String> from(final double[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+    public static Iterator<String> from(final boolean[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+    public static Iterator<String> from(final char[] src) {
+        return new Iterator<String>() {
+            private int idx = 0;
+
+            @Override
+            public boolean hasNext() {
+                return idx < src.length;
+            }
+
+            @Override
+            public String next() {
+                return "" + src[idx++];
+            }
+        };
+    }
+
+}
diff --git a/src/main/java/pl/mjaron/etudes/flat/StringSeries.java b/src/main/java/pl/mjaron/etudes/flat/StringSeries.java
@@ -19,23 +19,26 @@
 
 package pl.mjaron.etudes.flat;
 
+import pl.mjaron.etudes.Str;
+
 import java.util.ArrayList;
 import java.util.List;
 
+@Deprecated
 public abstract class StringSeries {
 
     public static <T> List<String> from(final List<T> objects) {
         final List<String> series = new ArrayList<>(objects.size());
         for (final T obj : objects) {
-            series.add(obj.toString());
+            series.add(Str.orEmpty(obj));
         }
         return series;
     }
 
     public static <T> List<String> from(final T[] objects) {
         final List<String> series = new ArrayList<>(objects.length);
         for (final T obj : objects) {
-            series.add(obj.toString());
+            series.add(Str.orEmpty(obj));
         }
         return series;
     }

diff --git a/...mjaron/etudes/flat/StringSeriesArray.java → .../mjaron/etudes/flat/StringSeriesList.java b/...mjaron/etudes/flat/StringSeriesArray.java → .../mjaron/etudes/flat/StringSeriesList.java
@@ -22,7 +22,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
-public abstract class StringSeriesArray {
+public abstract class StringSeriesList {
 
     public static <T> List<List<String>> from(final List<List<T>> rows) {
         final List<List<String>> stringTable = new ArrayList<>(rows.size());