http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); iz`ys.Fu
} Lo9 \[4FP
for(int i=0;i<nEndPos.length-1;i++) h*mKS -TC
{ z9zo5Xc=
nEndPos = nStartPos[i+1]; lF$$~G
} tkdyR1-
nEndPos[nEndPos.length-1] = nFileLength; uF T5Z
} c+<gc:#jy
} tQ2S*]"f
W6yz/{Rf
/ DST|2
//启动子线程 ZD8E+]+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pzDz@lAwR
for(int i=0;i<nStartPos.length;i++) V##TG0
{ * \tR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N)YoWA>#bF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :-b-)*TC;
nStartPos,nEndPos,i); R9Y{kk0M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JaJyH%+$!
fileSplitterFetch.start(); &([yI>%
} \@j3/!=,n%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &$pA,Gjin\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i]zTY\gw8M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dr#V^"Dte
nEndPos = " + nFileLength); ,j[1!*Z_[
// fileSplitterFetch[nPos.length-1].start(); `$r?^|T
,Q8h#0z r
/^[K
//等待子线程结束 l37l| xp~
//int count = 0; ,,Vuvn
//是否结束while循环 xT8!X5;
boolean breakWhile = false; zvbz3a
EJTa~
S%w67sGl4n
while(!bStop) OKNGV,{`
{ |Lz7}g=6
write_nPos(); .@f)#2
Utility.sleep(500); "(E%JAwZ^W
breakWhile = true; &."ltB
$K!6T
au7@-_
for(int i=0;i<nStartPos.length;i++) S2 YxA
{ <V4"+5cJ8
if(!fileSplitterFetch.bDownOver) ^|%7}=e
{ +PHuQ
breakWhile = false; _dn*H-5hO
break; boIFN;Aq"
} q%Lw#f
} ch0x*[N@
if(breakWhile) ~ZRtNL9
break; N|s8PIcSp
x@<!#d+
l65Qk2<YC
//count++; sQa9M
//if(count>4) )Z@hk]@?_[
// siteStop(); fH;lh-
} Oat #%
%lN4"jtx
jD_B&MQz
System.err.println("文件下载结束！"); IS }U2d,W
} O:[@?l
catch(Exception e){e.printStackTrace ();} VN<baK%]
} hKFB=U
[{rne2sA
q&EwD(k
//获得文件长度 N+ei)-
public long getFileSize() HlX2:\\
{ ]"\XTL0
int nFileLength = -1; VDPq3`$+v{
try{ PAy7b7m~B
URL url = new URL(siteInfoBean.getSSiteURL()); .h;X5q1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <p8>"~R
httpConnection.setRequestProperty("User-Agent","NetFox"); [E/^bM+
F#\+.inO
B*Q
int responseCode=httpConnection.getResponseCode(); \!'K#%]9
if(responseCode>=400) +Ram%"Zwh
{ b]5S9^=LI
processErrorCode(responseCode); '5SO3/{b
return -2; //-2 represent access is error %Z#[{yuFs
} Ya,(J0l
<e'l"3+9(
vTYgWR,h
String sHeader; }{ "RgT-qG
M9sB2Ips<
K/XUF#^B]
for(int i=1;;i++) 3x~AaC.j
{ :X-\!w\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #.~lt8F
//Utility.log(in.readLine()); [fXC ;c1
sHeader=httpConnection.getHeaderFieldKey(i); 05vu{>
if(sHeader!=null) ou'|e"tI
{ Ix|^c268o<
if(sHeader.equals("Content-Length")) pB0Do6+{
{ .2STBh.;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jQ\/R~)O
break; I KDh)Zm
} OL$^7FB
} fsVr<m
else +N!!Z2
break; 5v-o2
} O7tL,)Vv
} Nx4X1j?-n
catch(IOException e){e.printStackTrace ();} [$(/H;
catch(Exception e){e.printStackTrace ();} >CPoeIHK
Pr^p ^s
~m@w p
Utility.log(nFileLength); .)XJ-
s$;IR c5!6
aQhr$aH
return nFileLength; rlVo}kc7:
} i"C?6R
^Dhu8C(
&>o?0A6
//保存下载信息（文件指针位置） "J6aU
private void write_nPos() {uMqd-Uu
{ FUU/=)^P$
try{ X~Vr}
output = new DataOutputStream(new FileOutputStream(tmpFile)); >c:- ;(k
output.writeInt(nStartPos.length); ='|HUxFi
for(int i=0;i<nStartPos.length;i++) Z8Il3b*)
{ T~'9p`IW
// output.writeLong(nPos); vdN0YCXG
output.writeLong(fileSplitterFetch.nStartPos); 66~]7w
output.writeLong(fileSplitterFetch.nEndPos); Dhe ]f#d
} -,#LTW<.
output.close(); BHBMMjY5
} k/ ZuFTN
catch(IOException e){e.printStackTrace ();} yS:1F PA$_
catch(Exception e){e.printStackTrace ();} 2Md'<.
} IKV:J9
ZIrJ"*QO=
A?sU[b6_
//读取保存的下载信息（文件指针位置） HR83{B21
private void read_nPos() H/6GD,0
{ pu*vFwZ
try{ Y4|g^>{<ni
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qP0_#l&
int nCount = input.readInt(); j?n:"@!G/
nStartPos = new long[nCount]; ,o)U9<
nEndPos = new long[nCount]; Q-GnNT7MB3
for(int i=0;i<nStartPos.length;i++) hq^@t6!C\m
{ pJ1Q~tI
nStartPos = input.readLong(); 8QGj:3
nEndPos = input.readLong(); |.Pl[y
} 'qg q8
input.close(); mjqVP.
} /RmHG H!
catch(IOException e){e.printStackTrace ();} _}B:SM
catch(Exception e){e.printStackTrace ();} R?Or=W)i
} ~:%rg H
|cBpX+D
*AU"FI>V
private void processErrorCode(int nErrorCode) -cHX3UAEI
{ ?geEq'
System.err.println("Error Code : " + nErrorCode); ,\K1cW~U5
} /U%Xs}A)
S qQqG3F
sm>Hkci%
//停止文件下载 afMIqQ?
public void siteStop() JDzkv%E^
{ d>Z{TFY
bStop = true; *?+maK{5+
for(int i=0;i<nStartPos.length;i++) Y(]&j`%
fileSplitterFetch.splitterStop(); ,1YnWy*
#)BdN
k+S 6)BQ7U
} &,Xs=Lvmq
} vx\h Njb
//负责部分文件的抓取 X=p~`Ar M{
**FileSplitterFetch.java -R;.Md_
*/ WM}bM]oe
package NetFox; k'BLos1W
Ek,s6B)'d
f9FsZD
import java.io.*; hsQrHs'k
import java.net.*; Tdr^~dcQ
[-sE:O`yt
[N/[7Q/y
public class FileSplitterFetch extends Thread { u= K?K
snBC +`-
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String sURL; //File URL M,Px.@tw.
long nStartPos; //File Snippet Start Position *s6MF{Ds
long nEndPos; //File Snippet End Position pAV}hB
int nThreadID; //Thread's ID T@]vjXd![
boolean bDownOver = false; //Downing is over (r^IW{IndX
boolean bStop = false; //Stop identical /y,~?
FileAccessI fileAccessI = null; //File Access interface '* +]&~b
)]%GNdU
k:w\4Oqd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q*ZjOqj
{ {A(=phN
this.sURL = sURL; By@<N [I@
this.nStartPos = nStart; +mP3y~|-j
this.nEndPos = nEnd; eP3)8QC
nThreadID = id; d%9r"=/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NdQXQa?,
} H3.WAg[`
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*Df|D/,WE
public void run() Y1 i!
{ i)0*J?l=
while(nStartPos < nEndPos && !bStop) 'PlKCn`(w
{ nYuZg6K
jK&kQ
x]k^JPX
try{ M)#R_(Q5{
URL url = new URL(sURL); Ox&g#,@h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R9yK"
httpConnection.setRequestProperty("User-Agent","NetFox"); }tU<RvT
String sProperty = "bytes="+nStartPos+"-"; %t\`20-1<
httpConnection.setRequestProperty("RANGE",sProperty); VbtFM=Dg
Utility.log(sProperty); #cQ[ vE)y
vbQo8GFp}
S[NV-)r=
InputStream input = httpConnection.getInputStream(); oS$&jd
//logResponseHead(httpConnection); +gOCl*L
*kxk@(lT?
6yF4%Sz9
byte[] b = new byte[1024]; "_C^Bc
int nRead; yi7-[W}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nrA}36E
{ [6 !/
nStartPos += fileAccessI.write(b,0,nRead); {61NLF\0H
//if(nThreadID == 1) +6f5uMKUvs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ''wWw(2O
} -Tk~c1I#`
jjz<V(Sk
2u6N';jgZ
Utility.log("Thread " + nThreadID + " is over!"); DnaG$a<
bDownOver = true; Xt8;Pl
//nPos = fileAccessI.write (b,0,nRead); 1(!!EcU_
} Uz H)fB
catch(Exception e){e.printStackTrace ();} q[q#cY:0
} KI$?0O
} i<1w*yu
T{|'<KT
P,~a'_w:|D
//打印回应的头信息 qEf)TW(
public void logResponseHead(HttpURLConnection con) 'mug,jM
{ ,I@4)RSAH|
for(int i=1;;i++) "^<:7_Y
{ Qkk~{OuC
String header=con.getHeaderFieldKey(i); :H\6wJ
if(header!=null) z0HCmj9T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mw`%xID*
Utility.log(header+" : "+con.getHeaderField(header)); 8R:H{)o~s}
else `/]8C&u
break; =X>3C"]
} +&a2aEXF
} ygUvO3Z
0'|#Hi7@
*H&a_s/{Nb
public void splitterStop() Y.i<7pBt
{ *D,+v!wG9
bStop = true; '4FS.0*_
} PQvq$|q
3VA8K@QiRm
S5v>WI^0h
} Q_6./.GQ
nUhD41GJ
-j]r\EVKS
/* `U!eh1*b
**FileAccess.java ED"5y
*//文件访问(定位，写) Y#{KGVT<
package NetFox; ',6QL4qV/
import java.io.*; M5exo
R.|fc5_"+
F>n<;<
public class FileAccessI implements Serializable{ u;&`_=p
4m#i4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <5[wP)K@
RandomAccessFile oSavedFile; =[t([DG
long nPos; C+r--"Z
F.PD5%/$q
.XURI#b
public FileAccessI() throws IOException <pYGcVB9V
{ U`:#+8h-}
this("",0); 5:CC\!&QBV
} 9qwVBu ;
-1S+fUkiK/
wXXv0OzK
public FileAccessI(String sName,long nPos) throws IOException Xj+1]KRN
{ |mk$W$h
oSavedFile = new RandomAccessFile(sName,"rw"); j=dHgnVvj
this.nPos = nPos; PM=I
oSavedFile.seek(nPos); [JMz~~F
} }%$9nq3
IOTHk+w
0NpxqeIDY
public synchronized int write(byte[] b,int nStart,int nLen) )/bt/,M&}
{ S][:b
int n = -1; : [aUpX=
try{ A+Y>1-=JO
oSavedFile.write(b,nStart,nLen); Lkk'y})/
n = nLen; MZ+8wr/y
} Gk799SDL
catch(IOException e) t ~U&a9&Z
{ fn#b3ee
e.printStackTrace (); z~o%U&DO}
} AZl|; y
0[PPVr:
I.y|AQB
return n; l+R-lsj
} uA:;OM}
N<Y-]xS
vh?({A#>.E
} }6C&N8f
dW8'$!@!!
.__X[Mzth3
/* b*dRNu
**SiteInfoBean.java c0!bn b
*/ q*Ns]f'a
package NetFox; ((EN&X,v
(.%:Q0i1
7ou2SL}k
public class SiteInfoBean { |`qur5h`
?PyI#G
/o8`I m
private String sSiteURL; //Site's URL GsqrKrbJ
private String sFilePath; //Saved File's Path ttZ!P:H2
private String sFileName; //Saved File's Name W.zA1S
private int nSplitter; //Count of Splited Downloading File 4X#>;
Pm+H!x,
JsfbY^wz
public SiteInfoBean() H -.3r
{//nSplitter的缺省值为5 'OBAnE<.
//default value of nSplitter is 5 K{M_ 4'\
this("","","",5); @] )a
} "-v9V7KCM
g"#R>&P
)F4er'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .t"s>jq 1
{ 'cH),~ z
sSiteURL= sURL; vx!nC}f"k`
sFilePath = sPath; (X>r_4W$
sFileName = sName; :8Q6=K87
this.nSplitter = nSpiltter; "vU:qwm
!R{L`T0
']Y:f)i#
} T`a [~:
/MQd[03]
Am kHVg
public String getSSiteURL() C/!2q$
{ ]>R`]U9*O
return sSiteURL; xiA9X]FB
} _6=6 b!hD
.%WbXs
x0Tb7y`
public void setSSiteURL(String value) iKp4@6an
{ Pb]s+1
sSiteURL = value; N1#*~/sXh
} <-}6X
wQM(Lm#Q
C+y:<oo)
public String getSFilePath() y3;G<9K2c]
{ ix7N q7!N
return sFilePath; &)xoR4!2
} bmt2~!
ub,Sj{Mq"
wG^{Jf&@$
public void setSFilePath(String value) 5"XcVH4g
{ oh& PQ{
sFilePath = value; IWm|6@y
} aeH 9:GQ6
7|,5;
InPq1AH
public String getSFileName() ;"joebZ/
{ E@t~juF!
return sFileName; ,6a'x~y<r
} TmzEZ<} &7
x,>@IEN7
zpg*hlv
public void setSFileName(String value) 9-bDgzk
{ WNd(X}
sFileName = value; RMLs(?e
} DJrA@hm/Y
s'} oVx]
gtCd#t'(V
public int getNSplitter() q7m-} mBN~
{ !y4o^Su[
return nSplitter; -fG;`N5U
} O$#`he/jm
ajkRL|^
<k<
public void setNSplitter(int nCount) v C><N
{ lv$tp,+
nSplitter = nCount; AO8`ItNZdT
} ]<z>YyBA
} RE*UIh*O
pmQ9iA@=
(zgXhx_!D
/* 9.1%T06$
**Utility.java =GnDiI
*/ q1NAKcA<U
package NetFox; RUO,tB|(_;
6I_W4`<VeZ
dk{yx(Ty
public class Utility { ->K*r\T
4V<s"
|3"'>* J
public Utility() BhdJ/C^
{ kS=OX5
EkjO4=~UC
roW8 4x
} s:;!QIC5jo
Ds0^/bYp&
//线程睡眠 b.C!4^
public static void sleep(int nSecond) ;uDH&3W
{ }v@w(*)h:
try{ #,!.e
Thread.sleep(nSecond); (B,CL222x
} [",W TZ:
catch(Exception e) =wI,H@
{ ~{U~9v^v(
e.printStackTrace (); JsVW:8QO~
} PN0:,.4
} A9$q;8= <
qBKIl= ne
//日志 ETjlq]@j
public static void log(String sMsg) vxZz9+UbF
{ 2hmV1gj
System.err.println(sMsg); "{L%5:H@
} AP/5,M<
N55;oj_K
Ngh9+b6[
public static void log(int sMsg) Q@/wn
{ !cp ,OrO\
System.err.println(sMsg); -br/
} e[w)U{|40
} "E8-76n
'iUfr@
V:My1R0
/* <E$5LP;:
**TestMethod.java 'S@C,x%2,
*/ Qmzj1e$6x
package NetFox; >!`T=(u!
e)7[weGN
,C(")?4aJ
public class TestMethod { &``;1/J*W
_YO`x
@ZD1HA,h"
public TestMethod() *vUKh^="
{ ///xx/weblogic60b2_win.exe 0(:"q!h
try{ />K$_T/]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &[qLl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }UQBaqDH
SiteFileFetch fileFetch = new SiteFileFetch(bean); [S-NGip
fileFetch.start(); rv:,Os_
} $&k zix
catch(Exception e){e.printStackTrace ();} vL\wA_z"<H
XSn^$$S
GfL}f9
} r$R(4q:
(Dq3e9fX
f>-OwL($P
public static void main(String[] args) 73 D|gF*
{ QjF.U8
new TestMethod(); OHM.xw*?.
} &{/ `Q,
} p>|;fS\`@}
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