How to use

intern

method

in

java.lang.String

 String str=readString(); // read lengthy string any source db,textbox/jsp etc..
// This will place the string in memory pool from which you cant remove
str.intern();

private String intern(String s) {
 if (flags.intern) {
  return s.intern();
 } else {
  return s;
 }
}

private String intern(String s) {
 if (flags.intern) {
  return s.intern();
 } else {
  return s;
 }
}

public ExtractionObject(String objectId, 
  CoreMap sentence,
  Span span,
  String type,
  String subtype) {
 this.objectId = objectId;
 this.sentence = sentence;
 this.extentTokenSpan = span;
 this.type = type.intern();
 this.subType = (subtype != null ? subtype.intern() : null);
 this.attributeMap = null;
}

private String intern(String s) {
 if (globalFlags.intern) {
  return s.intern();
 }
 return s;
}

private void internStrings() {
 if (first != null) {
  first = first.intern();
 }
 if (second != null) {
  second = second.intern();
 }
}

private void checkInterning(String name) {
  if (namesInterned && name != name.intern()) {
    throw new IllegalArgumentException(
        "all names passed as arguments must be interned"
            + "when NAMES INTERNED feature is enabled");
  }
}

/**
 * Null-safe String intern method.
 * @return A canonical representation for the string object. Null for null input strings
 */
@Nullable
public static String intern(@CheckForNull String s) {
  return s==null ? s : s.intern();
}

public HeaderName(String name)
{
  if (name == null) throw new NullPointerException("HeaderName cannot be null!");
  this.name = SHOULD_INTERN ? name.intern() : name;
  this.normalised = SHOULD_INTERN ? name.toLowerCase().intern() : name.toLowerCase();
}

private static void addNumerals(TreeMap<String, Integer> map, int start, int end, Integer[] integers) {
  for (int i=start; i<=end; i++) {
    map.put(String.valueOf(i).intern(), integers[i]);
  }
}

private void addAllInterningAndPrefixing(Collection<String> accumulator, Collection<String> addend, String prefix) {
 assert prefix != null;
 for (String protoFeat : addend) {
  if ( ! prefix.isEmpty()) {
   protoFeat = prefix + protoFeat;
  }
  if (globalFlags.intern) {
   protoFeat = protoFeat.intern();
  }
  accumulator.add(protoFeat);
 }
}

/** Share data structure with other builds, mainly those of the same job. */
private PackedMap<String,String> compact(Map<String,String> record) {
  Map<String,String> b = new HashMap<String,String>();
  for (Entry<String,String> e : record.entrySet()) {
    b.put(e.getKey().intern(), e.getValue().intern());
  }
  return PackedMap.of(b);
}

/**
 * Normalizes a nonterminal contents.
 * This implementation strips functional tags, etc. and interns the
 * nonterminal.
 */
@Override
public String normalizeNonterminal(String category) {
 return cleanUpLabel(category).intern();
}

/**
 * Normalizes a nonterminal contents.
 * This implementation strips functional tags, etc. and interns the
 * nonterminal.
 */
@Override
public String normalizeNonterminal(String category) {
 return cleanUpLabel(category).intern();
}

protected String getFullName(String schemaName, String tableName) {
  StringBuilder sb = new StringBuilder();
  if (schemaName != null) {
    sb.append(appendEscape(schemaName)).append(DOT);
  }
  sb.append(appendEscape(tableName));
  return sb.toString().intern();
}

public String getSelectSql(String schemaName, String tableName, String[] pkNames, String[] columnNames) {
  StringBuilder sql = new StringBuilder("select ");
  int size = columnNames.length;
  for (int i = 0; i < size; i++) {
    sql.append(appendEscape(columnNames[i])).append((i + 1 < size) ? " , " : "");
  }
  sql.append(" from ").append(getFullName(schemaName, tableName)).append(" where ( ");
  appendColumnEquals(sql, pkNames, "and");
  sql.append(" ) ");
  return sql.toString().intern();// 不使用intern，避免方法区内存消耗过多
}

public String getDeleteSql(String schemaName, String tableName, String[] pkNames) {
  StringBuilder sql = new StringBuilder("delete from " + getFullName(schemaName, tableName) + " where ");
  appendColumnEquals(sql, pkNames, "and");
  return sql.toString().intern();// intern优化，避免出现大量相同的字符串
}

/**
 * Removes duplicate graphs from the set, using the string form of the graph
 * as the key (obviating issues with object equality).
 */
public static Collection<SemanticGraph> removeDuplicates(Collection<SemanticGraph> graphs) {
 Map<String, SemanticGraph> map = Generics.newHashMap();
 for (SemanticGraph sg : graphs) {
  String keyVal = sg.toString().intern();
  map.put(keyVal, sg);
 }
 return map.values();
}

public String getUpdateSql(String schemaName, String tableName, String[] pkNames, String[] columnNames) {
  StringBuilder sql = new StringBuilder("update " + getFullName(schemaName, tableName) + " set ");
  appendColumnEquals(sql, columnNames, ",");
  sql.append(" where (");
  appendColumnEquals(sql, pkNames, "and");
  sql.append(")");
  return sql.toString().intern(); // 不使用intern，避免方法区内存消耗过多
}

public HeaderName(String name)
{
  if (name == null) throw new NullPointerException("HeaderName cannot be null!");
  this.name = SHOULD_INTERN ? name.intern() : name;
  this.normalised = SHOULD_INTERN ? name.toLowerCase().intern() : name.toLowerCase();
}