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)); [PIh^DhK
} 7DZZdH$Fm
for(int i=0;i<nEndPos.length-1;i++) wbpz,
{ kEYkd@{
nEndPos = nStartPos[i+1]; DqJzsk'd3
} 6"oG bte
nEndPos[nEndPos.length-1] = nFileLength; <"hq}B
} ,I2x&Ys&.
} I^GZ9@UE
-=InGm\Y
I3.cy i
//启动子线程 _'mK=`>u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1CR)1H
for(int i=0;i<nStartPos.length;i++) 4=nh' U38
{ 8C=8Wjm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TFZxk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =h>jo&=Wad
nStartPos,nEndPos,i); oazY?E]}3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X:>,3[hx|
fileSplitterFetch.start(); jmBsPSGIC
} BhzcimC)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wM``vx[/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =c;.cW
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )i^S:2
nEndPos = " + nFileLength); [9C{\t
// fileSplitterFetch[nPos.length-1].start(); -NPX;e$<
h]vuBHJ}
ROr|n]aJj
//等待子线程结束 Kgw,]E&7
//int count = 0; %BwvA_T'Q
//是否结束while循环 AsfmH-4)
boolean breakWhile = false; r>lo@e0G
ZA7b;{o [
GUps\:ss
while(!bStop) 7Tc^}Q
{ !!<H*9]+W;
write_nPos(); n[gc`#7|{e
Utility.sleep(500); IMSLHwZ
breakWhile = true; PVi0|
a_\t(U
EX/{W$ &K
for(int i=0;i<nStartPos.length;i++) >aAsUL5W
{ A~@x8
if(!fileSplitterFetch.bDownOver) G.:QA}FE'
{ aeE~[m
breakWhile = false; WS.lDMYE7
break; 7n[0)XR>
} ,: Ij@u>)
} V X.9mt
if(breakWhile) g!;a5p6
break; Oh3A?!y#
T2_b5j3i
0V+v)\4FE
//count++; 4vi[hiV
//if(count>4) @6Z6@Pq(xQ
// siteStop(); IOY<'t+
} PQrc#dfc|
1b<[/g9
pwVaSnre`
System.err.println("文件下载结束！"); 7;a
} Z=beki]
catch(Exception e){e.printStackTrace ();} G4^6o[x
} <C_FRpR<f
1Q7]1fRu
|qf ef&
//获得文件长度 ZKJhmk
public long getFileSize() [ZL<Q
{ fLZ99?J
int nFileLength = -1; 6J <.i
try{ Ud_0{%@
URL url = new URL(siteInfoBean.getSSiteURL()); {$I1(DYN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ry40:;MYN
httpConnection.setRequestProperty("User-Agent","NetFox"); 'yR\%#s6
t4UL|fI
s)#TT9BbV
int responseCode=httpConnection.getResponseCode(); :)F0~Q
if(responseCode>=400) |#sY(1
{ U^kk0OT^
processErrorCode(responseCode); ),lE8A{ H
return -2; //-2 represent access is error k54b@U52 h
} ,+v>(h>q
-ZoAbp$
]]T,;|B
String sHeader; X2`n&JE
q}C;~nMD
d wku6lCk
for(int i=1;;i++) l6N"{iXU
{ ir~4\G!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1sq1{|NW~
//Utility.log(in.readLine()); :464~tHI[`
sHeader=httpConnection.getHeaderFieldKey(i); L-Mf{z
if(sHeader!=null) drJUfsxV
{ yJdkDVxYr
if(sHeader.equals("Content-Length")) \eXuNv_
{ ~&D5RfK5f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P:UR:y([
break; L0*f(H
} tlgg~MViS
} CYdYa|
else R]l2,0:
break; v7<r-<I[
} 5}2148
} F1/BtGvQE
catch(IOException e){e.printStackTrace ();} k/i&e~! \
catch(Exception e){e.printStackTrace ();} >6|Xvtf
@=K*gbq5
@DKph!cr
Utility.log(nFileLength); (d['f]S+&
|eksvO'~
0U!_o2]
return nFileLength; _pkmHj(
} Ue=1NnRDkA
,7;euV5X
,uZz?7mO
//保存下载信息（文件指针位置） 2>)::9e4
private void write_nPos() NW`Mc&
{ db.~^][k
try{ QEP|%$:i
output = new DataOutputStream(new FileOutputStream(tmpFile)); q&esI
output.writeInt(nStartPos.length); [x0*x~1B
for(int i=0;i<nStartPos.length;i++) G4%dah 5
{ %1rN6A!%
// output.writeLong(nPos); <FwAV=}6p
output.writeLong(fileSplitterFetch.nStartPos); 4{%-r[C9k
output.writeLong(fileSplitterFetch.nEndPos); Vg7BK%
} ,D'bIk
output.close(); HG3iK
} #(-?i\i
catch(IOException e){e.printStackTrace ();} 0QBK(_O`
catch(Exception e){e.printStackTrace ();} X(Lz&fkd
} vkLyGb7r<
?Skv2!X|
=-!B4G$
//读取保存的下载信息（文件指针位置） -Zqw[2Q4
private void read_nPos() ;pG5zRe
{ {?X9juc/#
try{ bLO^5`6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R.rE+gxO1
int nCount = input.readInt(); W7w*VD|
nStartPos = new long[nCount]; Fyc":{Jd
nEndPos = new long[nCount]; V5+|H1=
for(int i=0;i<nStartPos.length;i++) k>#-NPU$
{ ~zFwSF
nStartPos = input.readLong(); =g)SZK
nEndPos = input.readLong(); uf`/-jY
} 5oR)
input.close(); ]T%wRd5&-
} B]PG
catch(IOException e){e.printStackTrace ();} aL/7xa
catch(Exception e){e.printStackTrace ();} rji<g>GQ
} j^ttTq|l
VW:Voc
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private void processErrorCode(int nErrorCode) =j8g6#'u
{ L7N>p4h]Xj
System.err.println("Error Code : " + nErrorCode); )SfM`W)Y
} =!=DISPo
*s!T$oc
+Rq]_sDu
//停止文件下载 BWzo|isv
public void siteStop() ! ;R}=
{ (n2=.9k!
bStop = true; sX(rJLbD
for(int i=0;i<nStartPos.length;i++) `LJ.NY pP
fileSplitterFetch.splitterStop(); FwDEYG
(!T\[6
F "-GhjK
} MYUL y2)
} `'ak/%Krh
//负责部分文件的抓取 ZU5;w
**FileSplitterFetch.java n0w0]dJ&lc
*/ nW]T-!
package NetFox; Cp#}x1{
T>m|C}yy
^Fwdi#g
import java.io.*; M"8?XD%
import java.net.*; <^adt *m
#$JY&!M
B &)wJG
public class FileSplitterFetch extends Thread { OmaG|2u
mnM$#%q;%
da$ErN'{
String sURL; //File URL }SGb`l
long nStartPos; //File Snippet Start Position /+f3jy:d
long nEndPos; //File Snippet End Position 1P/4,D@
int nThreadID; //Thread's ID 78E<_UgcB
boolean bDownOver = false; //Downing is over U.J/ "}5`T
boolean bStop = false; //Stop identical !H`uN
FileAccessI fileAccessI = null; //File Access interface K}Lu1:~
}1YQ?:@
~.Cu,>fV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !3Q^oR
{ CjU?3Ag
this.sURL = sURL; (Uk\O`)m
this.nStartPos = nStart; CPu~^ik
this.nEndPos = nEnd; 9j$J}=y
nThreadID = id; rv%^2h<&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?I 7hbqQd
} D=~3N
_8OSDW*D5t
3$ BYfI3H
public void run() :JzJ(q/
{ kj!mgu#T
while(nStartPos < nEndPos && !bStop) |$c~Jq
{ L_fiE3G|>
iuEQ?fp
vtXZ`[D,l)
try{ ljjnqQ%
URL url = new URL(sURL); J\\o#-H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .Yxf0y?uv
httpConnection.setRequestProperty("User-Agent","NetFox"); ;V4f6[<]'z
String sProperty = "bytes="+nStartPos+"-"; 4|KtsAVp{
httpConnection.setRequestProperty("RANGE",sProperty); # |,c3$
Utility.log(sProperty); "@@Z{
e",0Er FT
@%[ VegT
InputStream input = httpConnection.getInputStream(); >Q|S#(c
//logResponseHead(httpConnection); PYW>
?.,2EC=+
x: 2 o$+v3
byte[] b = new byte[1024]; 9C\@10D
int nRead; .0]Odf:@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (J`EC
{ X8(WsN
nStartPos += fileAccessI.write(b,0,nRead); d]Mjr2h
//if(nThreadID == 1) SgY\h{{sP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a9TKp$LP`
} <84d Vg
s%t =*+L\
|1Pi`^
Utility.log("Thread " + nThreadID + " is over!"); rfhvdwwD
bDownOver = true; d# q8-
//nPos = fileAccessI.write (b,0,nRead); 3H@29TrJ+
} >A1;!kGE#
catch(Exception e){e.printStackTrace ();} ^|=3sJ4[U
} S&;D
} C07U.nzh
$rz'Ybs
uzWz+atH
//打印回应的头信息 y`-5/4
public void logResponseHead(HttpURLConnection con) C/A~r
{ [7gwJiK
for(int i=1;;i++) Ss#UX_DT_
{ T>pz?e^5&
String header=con.getHeaderFieldKey(i); 3dC;B@
if(header!=null) "SN+ ^`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 73kL>u
Utility.log(header+" : "+con.getHeaderField(header)); pN7 v7rs
else 2V=bE-
break; o|7 h
} kK$*,]iCp
} pt- 1>Ui
nN!R!tJPa
-WK
public void splitterStop() {-)*.l=
{ \o{rw0w0
bStop = true; 6T{SRN{
} UvM_~qo
UJ6zgsD1b?
5mB'\xGO2
} -[.A6W
dNgjM Q
6i_dL|c
/* :_"%o=
**FileAccess.java "N*i!h
*//文件访问(定位，写) Hnc<)_DF
package NetFox; j\.\ePmk]
import java.io.*; B5fF\N^
mL[Y{t#N
R3Ka^l8R|
public class FileAccessI implements Serializable{ ?br4 wl
R SqO$~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :T#"bY
RandomAccessFile oSavedFile; x$Tf IFy
long nPos; caC(KK#<
F_C_K"[s
(GI]Uyn
public FileAccessI() throws IOException f!aE/e\
{ !E|k#c9
this("",0); >gLLr1L\
} ;IX*4E'4s
B!zqvShF
O)Mf/P'
public FileAccessI(String sName,long nPos) throws IOException ^NPbD<~Lb
{ @%sr#YqY
oSavedFile = new RandomAccessFile(sName,"rw"); _F9O4Q4
this.nPos = nPos; +qzCy/_gd
oSavedFile.seek(nPos); FkJX)
} BbdJR]N/!h
V_-{TGKX
cPm-)/E)i
public synchronized int write(byte[] b,int nStart,int nLen) njN]0l{p
{ #cD20t
int n = -1; *.ZU" 5e
try{ CiSl0
oSavedFile.write(b,nStart,nLen); v5N2$Sqp*
n = nLen; .&Ok53]b
} {#'M3z=
catch(IOException e) auS.q5 %
{ I_h{n{,sr
e.printStackTrace (); lSk<euCYs
} @*rED6zH
5pI=K/-
bR;Zc
return n; 9M$N>[og
} M?fRiOj
';hTGLq\X
p&#*
} WgK|r~
bn$}U.m$-
:&oUI&(o
/* 'o*:~n
**SiteInfoBean.java &RP}w%I1
*/ 8xEOR!\!`k
package NetFox; Ft)Z'&L
J|BZ{T}d
;dh8|ujh
public class SiteInfoBean { BLvI[b|3gn
X;?Z_3I:5
VI(;8
private String sSiteURL; //Site's URL K{s%h0
private String sFilePath; //Saved File's Path n_Ka+Y<
private String sFileName; //Saved File's Name .V\M/q\Tv
private int nSplitter; //Count of Splited Downloading File {)vue0 vP
3koXM_4_{)
qWzzUM1=
public SiteInfoBean() Ph&fOj=pFb
{//nSplitter的缺省值为5 (BA2
//default value of nSplitter is 5 7Z;w<b~
this("","","",5); _x.D< n=X
} dWI.t1`i
VnJ-nfA
|=frsf~?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <9s=K\-
{ Q l$t
sSiteURL= sURL; s\`Vr;R:|
sFilePath = sPath; 4P>tGO&*x
sFileName = sName; ecH-JPm'
this.nSplitter = nSpiltter; `tkd1M
#NVqS5
Y,bw:vX
} YORFq9a{R
yMNLsR~rh
$J |oVVct
public String getSSiteURL() $<UX/a\sH
{ 4R U1tWQ%
return sSiteURL; B=;pyhc
} lbES9o5
LaE;{jY
id-VoHdK
public void setSSiteURL(String value) / -=(51}E
{ Zw5\{Z0
sSiteURL = value; s'^zudx
} a.5s5g)8
~PNO|]8j
P#H#@:/3
public String getSFilePath() -?b@6U
{ JXlFo3<
return sFilePath; dv0TJ 0%
} eh'mSf^=p
WRAW%?$
QD:0iD?
public void setSFilePath(String value) >:]fN61#
{ Siw9_c
sFilePath = value; 6QRfju'
} ~MY(6P
F_~-o,\
'KGY;8<x]
public String getSFileName() &,Q{l$`X
{ 2t { Cpw
return sFileName; {K'SOhH4?
} &1Fcwj
N,ik&NIWy
S'-<p<;D\B
public void setSFileName(String value) yj$S?B Ee
{ .Qh8I+Q%
sFileName = value; Hcd>\0
} 6\,^MI
Jb-wvNJu
BH0rT})
public int getNSplitter() ~~1~_0?e
{ Kc udWW]
return nSplitter; gE=~.P[ZX
} [Pp#l*
_3p:q.
/^[)JbgB
public void setNSplitter(int nCount) LO61J_J<
{ g}^/8rW
nSplitter = nCount; YY!(/<VI
} >2syF{`j
} %Y Rg1UKY
;D8Nya>%
[bPE?_a,
/* xdo{4XY^*W
**Utility.java ]bnxOk
*/ rF0zGNH
package NetFox; \wRr6-!_
0v7;ZxD
4_.k Q"'DH
public class Utility { lIjHd#q-C
el|t6ZT*
IPxfjBC+J
public Utility() eBAB7r/7
{ 3`9*Hoy0c
.`'SL''c
u}%&LI`.
} ,t+ATaOF
3X!~*_iC
//线程睡眠 F[=m|MZb
public static void sleep(int nSecond) H+5]3>O-$
{ h5F'eur
try{ Jj6kZK
Thread.sleep(nSecond); M.8!BB7\8e
} .sG,TLE[<
catch(Exception e) :ZP3$Dp
{ ~v54$#CB
e.printStackTrace (); >Au<y,Tw
} 5ZKnxEW,(
} ABHZ)OM
C(0Iv[~y/
//日志 Zj7XmkL
public static void log(String sMsg) *i?qOv/=>
{ \~)573'
System.err.println(sMsg); {H+?DMh
} m~U{ V9;*
Fp]8f&l8
D1Sl+NOV
public static void log(int sMsg) ^n2w6U0
{ C95,!q
System.err.println(sMsg); 3QHZC0AY
} 1I+5
} 9bNIaC*M
ibuI/VDF
OXacI~C
/* y*(YZzF
**TestMethod.java 2DC#PX)i
*/ 8Cqs@<r4Od
package NetFox; |@g1|OWd|
0/gcSW b
IcoL/7k3
public class TestMethod { d$TW](Bby
p_AV3
F:@Ixk?E
public TestMethod() Na6z,TW
{ ///xx/weblogic60b2_win.exe @ubz?5
try{ c~'kW`sNV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J9 =gv0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); % *G)*n
SiteFileFetch fileFetch = new SiteFileFetch(bean); I7~|!d6
fileFetch.start(); G'py)C5;
} Fq9[:
catch(Exception e){e.printStackTrace ();} (Lo2fY5
[dJ\|=
*YtNt5u
} uf^:3{1
DsX>xzM
~tLR
public static void main(String[] args) _5T7A><q<
{ @,MdvR+a
new TestMethod(); qj6`nbZ{va
} -"zu"H~t4
} i4I0oRp
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