Example usage for java.lang StringBuilder hashCode

Introduction

In this page you can find the example usage for java.lang StringBuilder hashCode.

Prototype

@HotSpotIntrinsicCandidate
public native int hashCode();

Source Link

Document

Returns a hash code value for the object.

Usage

From source file:org.loklak.geo.GeoMark.java

public GeoMark(final GeoLocation loc, final String salt) {
    super(loc.lat(), loc.lon(), loc.getNames(), loc.getISO3166cc());
    super.setPopulation(loc.getPopulation());

    // using the population, we compute a location radius
    // example city: middle-high density city (10,000 persons per square kilometer)
    // a large city in that density is Seoul, South Korea: 23,480,000 persons on 2,266 square kilometer
    // a circle with the area of 1 km^2 has the radius:
    // double r = Math.sqrt(1000000 / Math.PI); // meter
    // the radius required to hold the population is
    double r = Math.sqrt(loc.getPopulation() * 1000000 / 10000 / Math.PI); // meter
    // we don't compute a random number for the actual fuzzy location of the marker
    // to make this reproducible, we use a hash of the name and location
    StringBuilder hs = new StringBuilder(40);
    hs.append(loc.getNames().iterator().next());
    hs.append(loc.lat());//from w  w  w .  jav a2  s  .c  o  m
    hs.append(loc.lon());
    hs.append(salt);
    int h = Math.abs(hs.hashCode());
    if (h == Integer.MIN_VALUE)
        h = 0; // correction of the case that Math.abs is not possible
    // with that hash we compute an actual distance and an angle
    double dist = (h & 0xff) * r / 255.0d / 40000000 * 360; // 40 million meter (the earth) has an angle of 360 degree
    double angle = 2 * Math.PI * ((double) ((h & 0xfff00) >> 8)) / ((double) 0xfff);
    // now compute a point around the location on a circle for the mark
    this.mlat = this.lat() + Math.sin(angle) * dist;
    this.mlon = this.lon() + Math.cos(angle) * dist;
}

---

From source file:com.aliyun.datahub.flume.sink.RecordBuilder.java

public RecordEntry buildRecord(Map<String, String> rowData) throws ParseException {
    RecordEntry recordEntry = new RecordEntry(topic.getRecordSchema());
    for (Map.Entry<String, String> mapEntry : rowData.entrySet()) {
        String fieldName = mapEntry.getKey();
        if (!columnMappings.containsKey(fieldName)) {
            throw new RuntimeException("field name: " + fieldName + " not existed in datahub!");
        }/*from www.j av  a  2  s .co m*/
        Field field = columnMappings.get(fieldName);
        RecordUtil.setFieldValue(recordEntry, field, false, mapEntry.getValue(),
                columnDateformatMappings.containsKey(fieldName), dateFormat, configure.isBlankValueAsNull());
    }

    if (columnShardMappings.size() > 0) {
        StringBuilder hashKey = new StringBuilder();
        for (String col : configure.getShardColumnNames()) {
            hashKey.append(rowData.get(col));
        }
        int hashCode = hashKey.hashCode() & Integer.MAX_VALUE;
        recordEntry.setShardId(shardIds.get(hashCode % shardIds.size()));
    }

    return recordEntry;
}

---