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)); [E ]E
} c*@E_}C#
for(int i=0;i<nEndPos.length-1;i++) n .RhxgC<
{ w:<W.7y?0
nEndPos = nStartPos[i+1]; _}En/V_
} 9^p;UA
nEndPos[nEndPos.length-1] = nFileLength; 4BKI-;v$
} _n` a`2C|m
} i|m3mcI%2
6ZQwBS0Y
Q(oN/y3,
//启动子线程 ;{"+g)u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 81i655!Z
for(int i=0;i<nStartPos.length;i++) Sh8"F@P8
{ " _ka<R..
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }-6)gWe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vt9)pMs
nStartPos,nEndPos,i); +qwjbA+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L-k@-)98
fileSplitterFetch.start(); ynhmMy%
} ?CA,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "PpN0Rr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CLJ;<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", TBT:/Vfun
nEndPos = " + nFileLength); <h'5cO
// fileSplitterFetch[nPos.length-1].start(); oT>(V]*5
Yn G_m]
t>$kWd{9e;
//等待子线程结束 [a wjio
//int count = 0; %eO0wa$a
//是否结束while循环 ]3l9:|
boolean breakWhile = false; iB& 4>+N+
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-#HA"7XOE
while(!bStop) sH[ROm
{ u!W0P6
write_nPos(); +lMX{es\O
Utility.sleep(500); Y1J=3Y
breakWhile = true; ssN6M./6
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for(int i=0;i<nStartPos.length;i++) hK,Sf ;5V
{ pj?f?.^
if(!fileSplitterFetch.bDownOver) Xn%pNxUL
{ L>RP-x>
breakWhile = false; ]h %Wiw
break; u2?|Ue@[
} z3;*Em8Ir
} _zwG\I|Q
if(breakWhile) h9G RI
break; MfWyc_
(j3xAA
YS*9t Q{
//count++; -3=#u_
//if(count>4) !74S
// siteStop(); W|g4z7Pb
} hj.a&%
bKN@j'M
j?x>_#tIY
System.err.println("文件下载结束！"); +yD`3` E
} ?}U(3
catch(Exception e){e.printStackTrace ();} "\o+v|;
} )j0TeE1R
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7OJ'){R$
//获得文件长度 n+A?"`6*#
public long getFileSize() ikvWh<=>H
{ W1|0Yd ;P
int nFileLength = -1; PC-"gi=h
try{ +2&@x=xy
URL url = new URL(siteInfoBean.getSSiteURL()); a+Kj1ix
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `yH<E+
httpConnection.setRequestProperty("User-Agent","NetFox"); tAv@R&W,
e(GP^oK
mSb#Nn6W
int responseCode=httpConnection.getResponseCode(); Ke2ccN
if(responseCode>=400) [VsKa\9u
{ 0,89H4
processErrorCode(responseCode); V#S9H!hm$
return -2; //-2 represent access is error E(8* pI
} m;GbLncA
8)10o,#L
a@UZb
String sHeader; ,l:ORoND
*&^:T~|=!
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for(int i=1;;i++) |m^k_d!d
{ G(G{RAk>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~5CBEIF(NS
//Utility.log(in.readLine()); uYs5f.! `
sHeader=httpConnection.getHeaderFieldKey(i); 65#'\+
if(sHeader!=null) 1]@}|
{ C,ARXW1
if(sHeader.equals("Content-Length")) \1fN0e
{ \b?" b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vnM@QfN
break; P;qN(2L/=<
} q#,f 4P
} /7|V+6jV
else ; Q3n
break; 6sx'S?Qa*
} rMLp-aR'
} pxCK;]
catch(IOException e){e.printStackTrace ();} S/e2P|}
catch(Exception e){e.printStackTrace ();} C(#u[8
%}Ss,XJ
x:7b/j-
Utility.log(nFileLength); ?&63#B,iZ
/tf5Bv'<
!O:y@
return nFileLength; hog=ut
} d9;g]uj`
_lGdUt 2
|yQZt/*SOZ
//保存下载信息（文件指针位置） iB%gPoDCL@
private void write_nPos() w~"KA6^
{ o7sT=x9
try{ ->y J5smtY
output = new DataOutputStream(new FileOutputStream(tmpFile)); MbZJ;,e?
output.writeInt(nStartPos.length); N D(/uyI
for(int i=0;i<nStartPos.length;i++) #t:S.A@
{ XBb~\p3y
// output.writeLong(nPos); HUv/ ~^<
output.writeLong(fileSplitterFetch.nStartPos); C9n?@D;S
output.writeLong(fileSplitterFetch.nEndPos); kt["m.
} M42Ssn)
output.close(); K1\a#w
} @Z\,q's
catch(IOException e){e.printStackTrace ();} ][9%Kl*%@p
catch(Exception e){e.printStackTrace ();} DRp~jW(\y
} 1DE<rKI
clL2k8VS
qB0E_y)a
//读取保存的下载信息（文件指针位置） {B?Wu3-
private void read_nPos() !'&n-Q
{ @` 1Ds
try{ *E/`KUG]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); | r&k48@
int nCount = input.readInt(); &]v4@%<J
nStartPos = new long[nCount]; vY${;#~|
nEndPos = new long[nCount]; R`DKu=
for(int i=0;i<nStartPos.length;i++) Nn~~!q
{ jr /pj?
nStartPos = input.readLong(); x7:s]<kE
nEndPos = input.readLong(); PT=2@kH
} gcPTLh[^Er
input.close(); TarIPp
} ,9}h
catch(IOException e){e.printStackTrace ();} j.w@(<=x
catch(Exception e){e.printStackTrace ();} aI6$?wus
} h]5C|M|
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aB{vFTD5
private void processErrorCode(int nErrorCode) v/68*,z[
{ j53*E )d
System.err.println("Error Code : " + nErrorCode); h_:C+)13`x
} vq^f}id
F+,~v-
}z _
//停止文件下载 "$ Y_UJT7
public void siteStop() jkiFLtB@V
{ bx{$Y_L+p
bStop = true; w)kNkD
for(int i=0;i<nStartPos.length;i++) @eD):Y
fileSplitterFetch.splitterStop(); tD(7^GuR
+cgSC5nR
hbzC#@q
} wKZ$iGMbz
} \ 3wfwu.q
//负责部分文件的抓取 7\$qFF-y
**FileSplitterFetch.java 75"f2;
*/ -:2$ %
package NetFox; dJ2Hr;Lc
>/kcdWl
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import java.io.*; Q[vJqkgT
import java.net.*; Kwefs;<E?
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public class FileSplitterFetch extends Thread { s2'yY(u/
TUV&vz{
,SynnE68
String sURL; //File URL Szq/hv=Q
long nStartPos; //File Snippet Start Position < Z{HX[y
long nEndPos; //File Snippet End Position L;VoJf
int nThreadID; //Thread's ID Cjqklb/
boolean bDownOver = false; //Downing is over iop2L51eJ
boolean bStop = false; //Stop identical kzn5M&f>
FileAccessI fileAccessI = null; //File Access interface Vr6@>@SC
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cC=[Saatsf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Xu<k3oD7
{ f&eK|7J_Yf
this.sURL = sURL; kbTm^y"
this.nStartPos = nStart; f,V<;s
this.nEndPos = nEnd; @ezH'y-v
nThreadID = id; sYe?M,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R< ,`[*Z
} "= 6_V?&w
:3XA!o&.T3
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public void run() '(f&P=[b
{ #E?(vA1
while(nStartPos < nEndPos && !bStop) Mr;E<Lj ^K
{ ,k{#S?:b
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WG N=Y~E
try{ d F9!G;V
URL url = new URL(sURL); =yr0bGy`-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y4*U6+#.
httpConnection.setRequestProperty("User-Agent","NetFox"); pP*zq"o
String sProperty = "bytes="+nStartPos+"-"; C\/xl#e<@
httpConnection.setRequestProperty("RANGE",sProperty); co~Pyj
Utility.log(sProperty); f!oT65Vmi
%+8F'&X
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InputStream input = httpConnection.getInputStream(); ,TXTS*V?
//logResponseHead(httpConnection); W3IpHV
xC*6vH]?
T*#/^%HSG
byte[] b = new byte[1024]; Gb8D[1=u=
int nRead; ,4zmb`dP<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y? x,
{ @y='^DQ*
nStartPos += fileAccessI.write(b,0,nRead); >TOu|r
//if(nThreadID == 1) +W:=e,=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S0~2{G"v
} =U#dJ^4P
m@"QDMHk.
#JgH}|&a$
Utility.log("Thread " + nThreadID + " is over!"); W%T>SpFl
bDownOver = true; OK{quM5
//nPos = fileAccessI.write (b,0,nRead); tSVc|j
} qQA}Z*(m
catch(Exception e){e.printStackTrace ();} k5D%y3|9
} (@%gS[]
} V.O(S\
xl6,s>ob
7![,Q~Fy
//打印回应的头信息 M,/mE~
public void logResponseHead(HttpURLConnection con) o*DN4oa)
{ \@8+U;d
for(int i=1;;i++) Cnbz=z
{ v}1QH
String header=con.getHeaderFieldKey(i); 5jd,{<
if(header!=null) 1QLbf*zeIW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r<K(jG[:{f
Utility.log(header+" : "+con.getHeaderField(header)); GliwY_
else k.uMp<)D
break; zaah^.MA|
} MYla OT
} ^Wc@oa`
V}dJ.I /#
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public void splitterStop() AWP"b?^G|
{ ]|MEx{BG-
bStop = true; A%`[mc]4#
} k\WR ]
1#.>a$>
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} Qp/QaVQ+
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H*[M\gN$
/* 9?0^ap,T
**FileAccess.java ``ou/Z
*//文件访问(定位，写) JBJhG<J
package NetFox; W_kHj}dj,p
import java.io.*; kPVO?uO
`glBV`?^
UD8op]>L
public class FileAccessI implements Serializable{ xZ6~Ma2z
vH#huZA?7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g=;%
RandomAccessFile oSavedFile; |2abmuR0
long nPos; W}5xmz
kL$!E9
B?4boF?~
public FileAccessI() throws IOException xL{a
{ >N]7IU[-
this("",0); 95YL]3V
} %]>KvoA
pgOQIzu
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public FileAccessI(String sName,long nPos) throws IOException eu(:`uu
{ +tVaBhd!
oSavedFile = new RandomAccessFile(sName,"rw"); MFb9H{LA
this.nPos = nPos; ;~"FLQg@
oSavedFile.seek(nPos); 5<UVD:~z
} s (zL
gREzZ+([
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public synchronized int write(byte[] b,int nStart,int nLen) f ` R/ i
{ <4P4u*/o
int n = -1; B5X(ykaX~
try{ f6p-s y>
oSavedFile.write(b,nStart,nLen); G5CI<KRK#
n = nLen; *q()f\
} @>p<3_Y1
catch(IOException e) j!]YNH@
{ C}_ ojcR
e.printStackTrace (); hRs&t,{&
} CCL
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VzY8rI
return n; K?BOvDW"`
} B]uc<`f
CE/Xfh'44
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} EL(nDv
1IZ3=6
MBqt&_?K
/* JwAYG5W
**SiteInfoBean.java f}x.jxY?
*/ 22.8PO0
package NetFox; Bs O+NP
wM2*#
FLGk?.x$\
public class SiteInfoBean { fpFhn
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private String sSiteURL; //Site's URL 1+}{8D_F
private String sFilePath; //Saved File's Path 8C67{^`::
private String sFileName; //Saved File's Name 9Hf9VC3
private int nSplitter; //Count of Splited Downloading File vTJ}8
%k'!Iq+
c.>oe*+
public SiteInfoBean() :TJv=T'p'
{//nSplitter的缺省值为5 jO!y_Y]B
//default value of nSplitter is 5 yuat" Pg
this("","","",5); R}q>O5O
} r\/9X}y4z
UFp,a0|
:9^;Qv*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bdQ_?S(
{ d` jjGEj
sSiteURL= sURL; qzf!l"bT
sFilePath = sPath; 2T V X)q<\
sFileName = sName; m^GJuPLW
this.nSplitter = nSpiltter; Si6al78
LIZRoG8
ha(Z<
} .y@oz7T5
wPwXM!
*=+td)S/1
public String getSSiteURL() *#tJM.Z
{ ;|vpwB@B
return sSiteURL; <gJU?$
} :=wTvz
N4L|;?
^eR%N8Z
public void setSSiteURL(String value) h-Fn?
{ (`sH3&Kl
sSiteURL = value; "CUty"R8
} 1n:8s'\
?<(m 5Al7
[^U#Qj)hL
public String getSFilePath() d5D$&5Ec
{ n&-qaoNl
return sFilePath; 3b+d"`Y^S
} 9Hc$G{[a
$!8-? ?ML
PDrZY.-
public void setSFilePath(String value) =gJb^ Gx(w
{ ,'p2v)p^4
sFilePath = value; \H=&`?
} !+L/Khw/C
]y,==1To
rld67'KcE
public String getSFileName() `<\1[HJ\
{ X&0 uI*r
return sFileName; RV5n,J
} uWM{JEOl
\Dd-Xn_b
{ T-'t/0e(
public void setSFileName(String value) Gcig*5
{ BbgnqzU
sFileName = value; 1#0{@35
} ++V=s\d7
+;#Y]xy:
7tcPwCc{
public int getNSplitter() Kd=%tNp
{ ? P( ZA
return nSplitter; BI $
} m3mp/g.>
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public void setNSplitter(int nCount) /)4I|"}R0I
{ _g~qu [1
nSplitter = nCount; yp66{o
} {3.r6ZwCn
} OU/MiyP2
>]W)'lnO
> 3&: 5
/* o9F/y=.r=
**Utility.java K00 87}H
*/ s;64N'HH
package NetFox; /C4^<k\
<K8\n^i~c
wyQzM6:,yX
public class Utility { iv>SsW'p_
4*'pl.rb>
T)Y=zIQ1]7
public Utility() j& <i&
{ 6Qx#%,U^ J
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lhw ,J]0*
} I+dbZBX
FKT1fv[H
//线程睡眠 H<}^'#"p
public static void sleep(int nSecond) ;uW}`Q<
{ tPGJ<30
try{ \l.-eu'O
Thread.sleep(nSecond); ^",ACWF4Sk
} |jVM&R2s
catch(Exception e) =Q[b'*o7
{ Nqrmp" ]
e.printStackTrace (); 1f8GW
} -tyK~aasQ
} 4=Krq6{
H8`(O"V
//日志 1$81E.
public static void log(String sMsg) V2i@.@$j
{ _<NMyRJo
System.err.println(sMsg); FDv+*sZ
} a(v>Q*zNP
!}r% u."
NN1$'"@NL
public static void log(int sMsg) ^pe{b9c
{ +{L<? "
System.err.println(sMsg); YBP:q2H
} K!]1oy'V
} M>>qn_yq4
,i,q!M{-
v0ES;
/* [w&$|h:;
**TestMethod.java YI.w-K\
*/ `A,g] 1C:
package NetFox; A%{W{UP8N
LJ(1RK GCz
A^2Uzmzl?
public class TestMethod { &g~ wS@
KhW;RD
}GZ}Q5
public TestMethod() `p7&> BOA
{ ///xx/weblogic60b2_win.exe {nvLPUL
try{ GKFq+]W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3RR_fmMT)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1[t=XDz/e
SiteFileFetch fileFetch = new SiteFileFetch(bean); U=o"32n+
fileFetch.start(); ^=^z1M2P
} k!KDWb
catch(Exception e){e.printStackTrace ();} -~QHqU.
8-Hsgf.*
Z+StB15
} 3:f[gV9K
r@o6voX
0`I-2M4F*Q
public static void main(String[] args) DmBS0NyR7Y
{ ZKOXI%~Mc
new TestMethod(); {vN}<f`
} YNBHBK4;
} ,s_T pq
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