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)); owe362q
} k/nOz*
for(int i=0;i<nEndPos.length-1;i++) {! RW*B
{ JH2?^h|{
nEndPos = nStartPos[i+1]; cL*D_)?8
} ssW+'GD
nEndPos[nEndPos.length-1] = nFileLength; EWN$ILdD
} (]0$^!YK
} R!xs;|]
)!MeSWGq
lj.z>
//启动子线程 BQf}S +
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h$ M+Yo+
for(int i=0;i<nStartPos.length;i++) k]x64hgm
{ JGIN<J85e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~\hA-l36
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I/9ZUxQCyG
nStartPos,nEndPos,i); %" $.2O@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #{(?a.:
fileSplitterFetch.start(); !mpRLBH
} D8_m_M|P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'j$iSW&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); io cr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h 88iZK
nEndPos = " + nFileLength); f(DGC2R <
// fileSplitterFetch[nPos.length-1].start(); A<iF37.
e =& abu
q /|<>s
//等待子线程结束 yY*OAC
//int count = 0; H;s0|KRgJ
//是否结束while循环 uc%75TJ@
boolean breakWhile = false; -;T>4B=
/-4i"|
Z5Ao3O@
while(!bStop) :<%K6?'@^
{ mBc;^8I?23
write_nPos(); ,KkENp_
Utility.sleep(500); |LKhT4rE
breakWhile = true; .CI]8O"3y
;: Hfkyy]
{a_=4a
for(int i=0;i<nStartPos.length;i++) z>k6T4(
{ >0+m
if(!fileSplitterFetch.bDownOver) 133lIX+(k
{ {i^ ?XdM
breakWhile = false; {#q<0l
break; .D^k0V
} HeGGAjc
} xN2M|E]
if(breakWhile) M#})
break; /'E+(Y&:J
$${ebt
c@ En4[a'
//count++; *ok89ad
//if(count>4) ]V]~I.
// siteStop(); JU<<,0
} ix^:qw;
yqlkf$?
u 8U>R=M
System.err.println("文件下载结束！"); P%pB]d.qpi
} H` Q_gy5Z(
catch(Exception e){e.printStackTrace ();} a%ec: %
} 7H[#
n5UcivyX
(W3R3>;
//获得文件长度 abD55YJY
public long getFileSize() 0Qw?.#[9
{ =DE5Wq19
int nFileLength = -1; Q(AOKp,F
try{ 2b1LC!'U
URL url = new URL(siteInfoBean.getSSiteURL()); ..<(HH2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zDa*n:S
httpConnection.setRequestProperty("User-Agent","NetFox"); w[PW-m^`
h'UWf"d
oX3Q9)
int responseCode=httpConnection.getResponseCode(); xi;SKv;p
if(responseCode>=400) B_`A[0H
{ p(nC9NGB
processErrorCode(responseCode); fLc<}DF
return -2; //-2 represent access is error nT|fDD|
} S?hM
R9S7p)B
0g]ABzTn
String sHeader; lDp5aT;DsM
?xK9
Yl8tjq}iC
for(int i=1;;i++) 5[I> l
{ jSVb5P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .d8) *
//Utility.log(in.readLine()); 6JRee[
sHeader=httpConnection.getHeaderFieldKey(i); `ZV;Le'
if(sHeader!=null) d^]wqnpf
{ Ofqe+C
if(sHeader.equals("Content-Length")) '.WYs!
{ ?]kIztH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4,H}'@Db}
break; q7 Uu 8JXF
} ?Dd2k%o
} hpWAQ#%oHm
else HW.S~eLw*
break; qK|r+}g|&
} c)@M7UK[
} 4CX*
catch(IOException e){e.printStackTrace ();} 5I T'u3V
catch(Exception e){e.printStackTrace ();} BHZGQm
s}|IRDpp
o>U%3-+T^J
Utility.log(nFileLength); zRvYN
=*Wl;PI'
L$@RSKYp
return nFileLength; q#sMew\{
} UfcM2OmbK
* +A!12s@
&??(EA3
//保存下载信息（文件指针位置） =\X<UA}
private void write_nPos() oH6(Lq'q
{ n6Q 3X
try{ cY\-e?`=4
output = new DataOutputStream(new FileOutputStream(tmpFile)); s)/i_Oe$\
output.writeInt(nStartPos.length); .vpQ3m>
for(int i=0;i<nStartPos.length;i++) Qg9{<0{u
{ ~Gwn||g78
// output.writeLong(nPos); Kn\Oj=4
output.writeLong(fileSplitterFetch.nStartPos); 8l!S<RA
output.writeLong(fileSplitterFetch.nEndPos); L>@0Nne7
} Fdc bmQ
output.close(); 1`aFL5[0$
} 6_zL#7E'
catch(IOException e){e.printStackTrace ();} `;cKN)Xk
catch(Exception e){e.printStackTrace ();} vNE91
} / d6mlQS
i7 p#%2
}b\d CGVr
//读取保存的下载信息（文件指针位置） i9.52
private void read_nPos() db#y]>^l
{ LgUaX
try{ !\|&E>Gy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |":^3
int nCount = input.readInt(); b.Y[:R_9&
nStartPos = new long[nCount]; [gv2fqpP
nEndPos = new long[nCount]; n4Q!lJ
for(int i=0;i<nStartPos.length;i++) uY "88|
{ ;Kkn7&'F
nStartPos = input.readLong(); :4Q_\'P
nEndPos = input.readLong(); BIcE3}dS8
} mGL%<4R,
input.close(); 0JNG\ARC
} d6hWmZVC
catch(IOException e){e.printStackTrace ();} L]HY*e
catch(Exception e){e.printStackTrace ();} @*%.V.
} h+Dg"j<[
3)Paf`mr
lfj>]om$
private void processErrorCode(int nErrorCode) ^=R>rUCmv
{ Nu9mK
System.err.println("Error Code : " + nErrorCode); {Lq uOC1
} O^:Rm=,$
Y/@4|9!
_v2FXm
//停止文件下载 KbwWrf>
public void siteStop() $fnFi|-
{ R )?8A\<E
bStop = true; :_Ng`b/
for(int i=0;i<nStartPos.length;i++) U4LOe}Ny
fileSplitterFetch.splitterStop(); aNXu"US+Sp
%X[|7D-
=BX<;vU
} xhqIE3gd
} 7J>n;8{%?
//负责部分文件的抓取 lZ_i~;u4@v
**FileSplitterFetch.java bcj7.rh]'h
*/ 9.%{M#j
package NetFox; oz[E>%
Keof{>V=CA
v5<Ext rV
import java.io.*; t[an,3
import java.net.*; uOW9FAW
umls=iz
_/MKU!\l
public class FileSplitterFetch extends Thread { ~9'VP}\
z@iY(;Qo
l|N1u=Z
String sURL; //File URL MR+ndB<
long nStartPos; //File Snippet Start Position z),l&7
long nEndPos; //File Snippet End Position ] YQ*mvI]
int nThreadID; //Thread's ID :_H$*Q=1
boolean bDownOver = false; //Downing is over GD*6tk;5/
boolean bStop = false; //Stop identical fMLm_5(H
FileAccessI fileAccessI = null; //File Access interface Yq;S%.
},[j+wx
=VY[m-q5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @~a52'\
{ OkFq>;{a
this.sURL = sURL; pV>/"K
this.nStartPos = nStart; bLNQ%=FjO
this.nEndPos = nEnd; < ^J!*>
nThreadID = id; "t\rjFw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6dg[
} NrL%]dl3/
C{Npipd}v
tk, HvE
public void run() =<33(
{ vEfX'gyk
while(nStartPos < nEndPos && !bStop) RHB>svT^K>
{ L2K4nTA
0n3O;=[aV
yil{RfBEr_
try{ i>e75`9
URL url = new URL(sURL); GbNVcP.ocP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y< 146
httpConnection.setRequestProperty("User-Agent","NetFox"); Vw)\#6FL
String sProperty = "bytes="+nStartPos+"-"; e@X~F6nP
httpConnection.setRequestProperty("RANGE",sProperty); O'5(L9,
Utility.log(sProperty); B VPf8!-
<pPI:D@G
P^1rNB
InputStream input = httpConnection.getInputStream(); r*,]=M W
//logResponseHead(httpConnection); :.sK:W("v
1S_KX.
}b,a*4pN
byte[] b = new byte[1024]; >xH3*0Lp
int nRead; Grw_SVa^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;GE0iSC
{ &|9?B!,`
nStartPos += fileAccessI.write(b,0,nRead); 1` 9/[2z
//if(nThreadID == 1) rVf`wJ6b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jP}N^
} R\X=Vg
Dy8Go4
?mF-zA'4]
Utility.log("Thread " + nThreadID + " is over!"); mXa1SZnE
bDownOver = true; GU"MuW`u2
//nPos = fileAccessI.write (b,0,nRead); 'l<kY\I!%
} [x)BQX'
catch(Exception e){e.printStackTrace ();} F]YPq
} eH1Y!&`
} 2gFQHV
J/ rQ42d
Uvz9x"0[u
//打印回应的头信息 H[6d@m- Z
public void logResponseHead(HttpURLConnection con) LFh(. }
{ g\6(ezUF*
for(int i=1;;i++) *!nS4[d
{ [vIO
String header=con.getHeaderFieldKey(i); RNIfw1R
if(header!=null) K$K[fcj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5Pv>`E2^
Utility.log(header+" : "+con.getHeaderField(header)); 7f 7*id
else Xv'64Nc!;
break; 5F0sfX
} \w`Il"}V
} +LX&1GX
.0s/O
Lp{l&-uQ
public void splitterStop() ,',fO?Qv'
{ "w|GIjE+
bStop = true; .>H7i`1D`
} `#9ZP
UkeW2l`:
)_f "[m%
} wdp4-*
c.d*DM}W
\WZ00Y,*
/* p%,JWZ[
**FileAccess.java x#pTB.
*//文件访问(定位，写) >r{,$)H0
package NetFox; 1_<'S34
import java.io.*; zzPgLE55
..n-&(c32
!m^WtF
public class FileAccessI implements Serializable{ 6Lz&"C,`
Bv/v4(G5g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Yz{UP)TC
RandomAccessFile oSavedFile; R=PjLH&)
long nPos; i%-c/ lop
Q@l3XNH|c
^>]p4Q3 6
public FileAccessI() throws IOException bD49$N?>
{ Na[bCt
this("",0); HgG"9WBe%
} sd#a_
h`jtmhoz
,wnF]K2D0
public FileAccessI(String sName,long nPos) throws IOException i\,#Z!
{ Xf$,ra"
oSavedFile = new RandomAccessFile(sName,"rw"); kbOo;<X9A
this.nPos = nPos; VE{t]>*-u
oSavedFile.seek(nPos); \t )Zk2
} c)lMi}/
*y.KD4@{
O^`Y>>a
public synchronized int write(byte[] b,int nStart,int nLen) PBkKn3P3
{ 'p{>zQ\5
int n = -1; 3D%I=p(
try{ E#ti
oSavedFile.write(b,nStart,nLen); m-ZVlj
n = nLen; fq\E$'o$
} $g#%
catch(IOException e) P^.L0T5g
{ G?YKm1:w
e.printStackTrace (); h5B'w
} z^=9%tLJ
yPuT%H&i
3<?(1kSo>>
return n; _%"/I96'
} -CxaOZG
)<jj O
~ dmyS?Or
} o- GHAQ
&e2") 4oh
1oodw!hW
/* Qv[@ioc
**SiteInfoBean.java 8]+hfB/
*/ 8+ Hho@=
package NetFox; U%U%a,rA5s
dp-8,Seu
i wK,XnIR
public class SiteInfoBean { 6(X(f;MEl
%'@&j2j>
e|xRK?aVBu
private String sSiteURL; //Site's URL r@k&1*&
private String sFilePath; //Saved File's Path 9<,\+}^{
private String sFileName; //Saved File's Name CCQ<.iCU
private int nSplitter; //Count of Splited Downloading File I?5#Q0,b
F8/4PB8-
Q>= :$I
public SiteInfoBean() 8"RX~Igf
{//nSplitter的缺省值为5 APy&~`
//default value of nSplitter is 5 7e>n{rl
this("","","",5); r!j_KiUy
} ~eE2!/%9
z l@ <X0q
/ey}#SHm,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8 w^i
{ dN;C-XF3s
sSiteURL= sURL; 1;g>?18@
sFilePath = sPath; :/d#U:I
sFileName = sName; Bo)w#X
this.nSplitter = nSpiltter; O`Nzn~),x
} n_9d.
D+#QQH
} 4GeWo@8h
w}YO+
x4R[Q&:M
public String getSSiteURL() U $e-e/
{ !&?(ty^F
return sSiteURL; @My-O@C>
} 1i^!A&
*)H?d
x>Q\j>^
public void setSSiteURL(String value) .@.O*n#K
{ >>FE?@
sSiteURL = value; 9;sebqC?
} @aWvN;v
4*G#fW-
Mp}aJzmkB;
public String getSFilePath() j^mAJ5
{ g]N!_Ib/!
return sFilePath; Z2j M.[hq
} [*]&U6\j
?%{v1(
&0+;E-_
public void setSFilePath(String value) M&:[3u-
{ Ihw^g<X
sFilePath = value; Yfs60f
} t1wNOoRa
S:+SZq
}p]8'($
public String getSFileName() fiES6VL
{ C`%cPl
return sFileName; m\O<Yc keA
} 9)];l?l
+MvcW.W~
Qis[j-?:
public void setSFileName(String value) u @?n3l
{ n&pi
sFileName = value; v#8{pr
} ofC=S$wX
'n6D3Vse
sy0|=E*;8"
public int getNSplitter() Fr`"XH
{ PsjSL8]
return nSplitter; ,W'`rCxJ
} 8rx?mX,}
,-rOfk\u
m+?$cyA>v
public void setNSplitter(int nCount) 1}%vZE2
{ [z5pqd-
nSplitter = nCount; x9hkE!{8
} ocotO
} 5RrzRAxq
{r yv7G
&"p7X>bd
/* /xUTm=w7u
**Utility.java {U=Mfo?AH
*/ )! Jo7SR
package NetFox; yM`J+tq
Y(h86>z*w
p~J|l$%0rQ
public class Utility { Po~{Mpe
...|S]a
|:7O
public Utility() :70[zo7n'
{ Bvk 8b
s{#rCc)
P+tRxpz
} +*Y/+.4WE$
F=?0:2P0bD
//线程睡眠 e*{'A
public static void sleep(int nSecond) "j#;MOK
{ j*B,b4
try{ KzZ|{!C
Thread.sleep(nSecond); HC_+7O3A
} "#Qqwsw7
catch(Exception e) #&u9z5ywM
{ j>Ce06G
e.printStackTrace (); )zzZYs&|
} Kx==vq%39
} >c %*:a
qS1byqq78l
//日志 'M8wjU
public static void log(String sMsg) xn|M]E1)
{ "ld4v+o8l
System.err.println(sMsg); 9ozN$:
} F6^Xi"R[
_=!Rl#
]06orBV
public static void log(int sMsg) uJhB>/Og
{ " iAwD8-
System.err.println(sMsg); 4BF \-lq~
} L+VqTt
} W/e6O??O
~U"puEftbs
b/"&E'5-`\
/* 'b1k0 9'
**TestMethod.java StZ GKY[Q
*/ mu`:@7+Yp
package NetFox; NNDW)@p6z
}h{8i_R
CNP!v\D
public class TestMethod { b`:n i
4k%y*L
LGuK@^
public TestMethod() m ioNMDG
{ ///xx/weblogic60b2_win.exe sKDsps^$
try{ LkvR]^u0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &/wd_;d^A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X^Dklqqy
SiteFileFetch fileFetch = new SiteFileFetch(bean); nSR7$yS_
fileFetch.start(); 9=RfGx
} A:Y ([
catch(Exception e){e.printStackTrace ();} +8p4\l$<`
pSMF1Oy
FLf< gz
} A<$~Q;r2a
&=ZVU\o:
dZMf5=tb
public static void main(String[] args) `hpX97v
{ :xwyE(w
new TestMethod(); 'LC-/_g
} vT1StOx<V
} iG+hj:5
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