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)); iG{xDj{CKv
} 6^,;^
for(int i=0;i<nEndPos.length-1;i++) %\1W0%w
{ O~5*X f
nEndPos = nStartPos[i+1]; EuKkIr/(
} =BO>Bi&&
nEndPos[nEndPos.length-1] = nFileLength; C:vVFU|4
} 4=l$wg~;
} fy>~GFk(
`>HrO}x^
x.q"FXu
//启动子线程 &iaS3x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3#{Al[jq
for(int i=0;i<nStartPos.length;i++) 5>fAO =u!Q
{ Z1U@xQj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I(qFIV+HR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CE|rn8MB
nStartPos,nEndPos,i); Lr*\LP6jx3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [$`%ve
fileSplitterFetch.start(); }k@SmO8
} mv#*%St5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tPFj[Y~Iy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O0sLcuT$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vSwRj<|CF
nEndPos = " + nFileLength); (~?p`g+I.P
// fileSplitterFetch[nPos.length-1].start(); [`!%u3
n"Wlfd0
,3Aiz|v-
//等待子线程结束 scy_
//int count = 0; V=H:`n3k
//是否结束while循环 Bm+Ca:p%
boolean breakWhile = false; +?6@%mW'
Bk/&H-NI
&& b;Wr
while(!bStop) xks Me
{ 2k^'}7G%
write_nPos(); {vp*m:K
Utility.sleep(500); [G"Va_A8
breakWhile = true; r"`7ezun:
kTm}VTr 1
gCx#&aXS
for(int i=0;i<nStartPos.length;i++) 2u(G:cR
{ sE[ Yg8yAt
if(!fileSplitterFetch.bDownOver) h*\u0yD)
{ bv}e[yH
breakWhile = false; f8)fm2^09
break; BR:Mcc
} *eMMfxFl
} C40o_1g
if(breakWhile) 8Y/1+-
break; (P-$tHt
y N,grU(
k\-h-0[|
//count++; ur[^/lxx0
//if(count>4) kG`&Z9P
// siteStop(); dEZlJo@J
} XmN8S_M>v
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wv^n#
System.err.println("文件下载结束！"); M<P8u`)>4H
} :a9
catch(Exception e){e.printStackTrace ();} tNz(s)
} VPb8dv(a3
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xcH&B%;f
//获得文件长度 9A *gW j
public long getFileSize() ]D,\(|
{ 4B)%I`
int nFileLength = -1; [OR"9W&
try{ Yh;A)Np
URL url = new URL(siteInfoBean.getSSiteURL()); KCnm_4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6i@* L\ Dl
httpConnection.setRequestProperty("User-Agent","NetFox"); kq@~QI?9
/dHIm`. Z
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int responseCode=httpConnection.getResponseCode(); `yO'-(@"gY
if(responseCode>=400) BO.Db``
{ &_74h);2I:
processErrorCode(responseCode); ~yJJ00%
return -2; //-2 represent access is error %Rk DR
} Z}.ZTEB
Z{1B:aW
MfO:BX@$
String sHeader; BlqISyrY
&d\ y:7
*q+X?3
for(int i=1;;i++) "<LWz&e^^
{ A#Y:VavQ?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1x%B`d
//Utility.log(in.readLine()); ?hViOh$.
sHeader=httpConnection.getHeaderFieldKey(i); $=) Pky-~
if(sHeader!=null) gFsqCx<q
{ Z58{YCY
if(sHeader.equals("Content-Length")) n]i#&[*A(
{ Sb(OG 6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Hz)i.AA 4
break; Xt +9z
} (>NZYPw^3
} b`@J"E}
else :>U+HQll
break; p}<60O"r$
} wE}Wh5
} =[LorvX+
catch(IOException e){e.printStackTrace ();} 7*"Jx}eM
catch(Exception e){e.printStackTrace ();} [2h.5.af
MdmN7>
!#=3>\np+X
Utility.log(nFileLength); P^tTg
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return nFileLength; !-%XrU8o3
} " m13HS
keFH CC
2t PfIg
//保存下载信息（文件指针位置） {Ay dt8
private void write_nPos() "%p7ft
{ T^(> 8/O
try{ _54gqD2C,
output = new DataOutputStream(new FileOutputStream(tmpFile)); } !y5hv!_
output.writeInt(nStartPos.length); LD1&8kJ*l
for(int i=0;i<nStartPos.length;i++) cnI5G!
{ @bJIN]R
// output.writeLong(nPos); ^39lUKL
output.writeLong(fileSplitterFetch.nStartPos); v; R2,`[W
output.writeLong(fileSplitterFetch.nEndPos); ~?FhQd\Q
} gn&Zt}@[
output.close(); imeE&
} Hf\sF(, (
catch(IOException e){e.printStackTrace ();} kguZAO6
catch(Exception e){e.printStackTrace ();} +@~WKa
} 6su~SPh
|<5F08]v
Fm,` ]CO
//读取保存的下载信息（文件指针位置） `j(._`8%a
private void read_nPos() /R&h#;l
{ Gx6%Z$2n
try{ zRou~Kxi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o+7)cI
int nCount = input.readInt(); =/`]lY&
nStartPos = new long[nCount]; oeB'{bG
nEndPos = new long[nCount]; cR_pC 9z
for(int i=0;i<nStartPos.length;i++) D}LM(s3li7
{ OF+4Mq
nStartPos = input.readLong(); R TpNxr{[
nEndPos = input.readLong(); P^Owgr=Y
} -0x Q'1I
input.close(); x7U=1y(
} XbB(<\0+
catch(IOException e){e.printStackTrace ();} P_w4 DU
catch(Exception e){e.printStackTrace ();} ".N+nM~
} p@nj6N.--
{:|3V 7X
%1.F;-GdsW
private void processErrorCode(int nErrorCode) YO$D-
{ f&mi nBU
System.err.println("Error Code : " + nErrorCode); BdF/(Pg
} yCvtglAJ4
brs`R#e \
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//停止文件下载 7HBf^N.
public void siteStop() &i(Ip'r
{ KE@+I.x
bStop = true; 5a$EXV
for(int i=0;i<nStartPos.length;i++) [`t ;or
fileSplitterFetch.splitterStop(); C5Q!_x(
U/^#nU.,
b%%r`j,'JE
} tP7<WGHd/
} S`U8\KTi
//负责部分文件的抓取 o3/o2[s
**FileSplitterFetch.java #-<Go'yF
*/ 4&sf{tI
package NetFox; ?'z/S5&j
CV.|~K0O
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import java.io.*; Xt<1b
import java.net.*; lz~^*\ F
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"(7y%TFt:
public class FileSplitterFetch extends Thread { A*?PH`bY
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j2<+[h-
String sURL; //File URL .R)P |@z L
long nStartPos; //File Snippet Start Position YHQ]]#'
long nEndPos; //File Snippet End Position hm! J@
int nThreadID; //Thread's ID jts0ZFHc-
boolean bDownOver = false; //Downing is over zR?R,k)m
boolean bStop = false; //Stop identical 6dR+qJa6i
FileAccessI fileAccessI = null; //File Access interface jJ$B^Y"4
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1vj@qw3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4d5c]%
{ aC\f;&P>
this.sURL = sURL; z&amYwQcI
this.nStartPos = nStart; 9 A ?{}c
this.nEndPos = nEnd; =wdh#{
nThreadID = id; R+Hu?Dv&F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |p&EP2?T
} BZ?3=S1*
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public void run() "dX~J3$
{ DOKe.k
while(nStartPos < nEndPos && !bStop) kg]6q T;Y
{ J 7R(X
J&>@>47
5MB`yRVv
try{ I]v2-rB&-
URL url = new URL(sURL); P);s0Y|@H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?f"5yQ-B
httpConnection.setRequestProperty("User-Agent","NetFox"); TjTG+uQ
String sProperty = "bytes="+nStartPos+"-"; sip4,>,E
httpConnection.setRequestProperty("RANGE",sProperty); G|rE\h 2w
Utility.log(sProperty); :@[\(:
f47]gtB-
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InputStream input = httpConnection.getInputStream(); ju{Y6XJ)
//logResponseHead(httpConnection); B-rE8\
b?i+nhqI
CvY+b^;
byte[] b = new byte[1024]; hTX[W%K
int nRead; Bdt6 w(`^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &L+uu',M0c
{ \Mg_Q$
nStartPos += fileAccessI.write(b,0,nRead); <bzzbR[F
//if(nThreadID == 1) "=Br&FN{|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1P!)4W
} [P`e@$
mZR3Hl$
#{q.s[g*+1
Utility.log("Thread " + nThreadID + " is over!"); d2`g,~d
bDownOver = true; P"_/P8
//nPos = fileAccessI.write (b,0,nRead); RhE~-b[X
} Ik0g(-d
catch(Exception e){e.printStackTrace ();} (?|M'gZ
} p"ytt|H
} p0@^1
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v745FIy<
//打印回应的头信息 z$%twBg}#
public void logResponseHead(HttpURLConnection con) eIkKsgr>
{ Food<(!.>
for(int i=1;;i++) ^<CVQ8R7
{ `pfIgryns
String header=con.getHeaderFieldKey(i); *U[yeE].
if(header!=null) @Dh2@2`>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FOXSs8"c]!
Utility.log(header+" : "+con.getHeaderField(header)); l*1|B3#m!
else k7CKl;Fck
break; ' P?h?w^T
} faQmkO
} !RI _Uph
~5N}P>4*
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public void splitterStop() bC<W7qf]}
{ Y$=jAN
bStop = true; bE_8NA"2
} j]BRfA
g_Z tDxz
L.HeBeO
} puC91
;,&cWz
3v8LzS3@
/* vgwpuRL5b
**FileAccess.java U] LDi8
*//文件访问(定位，写) 5'} V`?S
package NetFox; 1F@j?)(
import java.io.*; v-{g
UT<e/
u:l-qD9=(
public class FileAccessI implements Serializable{ entU+Or
-'&/7e6>y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [;u#79aE
RandomAccessFile oSavedFile; MR#*/Iw~
long nPos; za_b jE
tk"+ u_uw
nuce(R
public FileAccessI() throws IOException X94a
{ mJSfn"b}K
this("",0); c#n 2!
} }s~c(sL?;
Y sM*d
OIcXelS:@k
public FileAccessI(String sName,long nPos) throws IOException `z&#|0O
{ #a8kA"X
oSavedFile = new RandomAccessFile(sName,"rw"); .IeO+RDQ
this.nPos = nPos; bKQho31a'
oSavedFile.seek(nPos); M-o'`e'
} WMB%?30
2*:q$c
n>Ff tVZNJ
public synchronized int write(byte[] b,int nStart,int nLen) s<O$ Y
{ ~aob@(
int n = -1; 8SGaS&
try{ 9wvlR6z;u
oSavedFile.write(b,nStart,nLen); QQ(}71U
n = nLen; L+am-k:T~
} 3Ua?^2l
catch(IOException e) RzEzNV
{ b#VtPn]
e.printStackTrace (); 3!CUJs/W
} I1Q!3P
GcBqe=/B!
Yuvi{ 0
return n; }v ZOPTP
} *1)>He$qL
GJ ^c^`
./YR8#,
} }HgG<.H>
@>2pY_
+9_Y0<C
/* &hOz(825r
**SiteInfoBean.java SVCh!/qe\
*/ MGg(d
package NetFox; ]fyfL|(;
V1aP_G-:
hOj{y2sc
public class SiteInfoBean { @62T:Vl
'}.Yf_
/R#zu_i
private String sSiteURL; //Site's URL ">H*InF
private String sFilePath; //Saved File's Path {9x_E {
private String sFileName; //Saved File's Name t<H"J__&
private int nSplitter; //Count of Splited Downloading File At Wv9
@*6fEG{,q
\x<8
public SiteInfoBean() g)X3:=['
{//nSplitter的缺省值为5 /fI}QY1
//default value of nSplitter is 5 1dH|/9
this("","","",5); ^? fOccfQ{
} =xI;D,@S
IKD{3cVL
cn'>dz3v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m:H^m/g
{ m^A2 8X7
sSiteURL= sURL; Blpk n1
sFilePath = sPath; xTHD_?d
sFileName = sName; TGCB=e
this.nSplitter = nSpiltter; S$mv(C
!=[Y yh
q}{E![ZTu
} ) c@gRb~
8D*7{Q
1.3#PdMR,
public String getSSiteURL() q W(@p`
{ M:+CW;||!
return sSiteURL; ,-UF5U
} ,Z`}!%?
H/,KY/>i
eaw!5]huu
public void setSSiteURL(String value) ^m\o(R
{ 8g#$Y2P
sSiteURL = value; LmrdVSs_
} &.A_d+K&
wi2`5G6|z
^z?b6kTC
public String getSFilePath() (v]%kXy/G
{ 3?93Pj3oPt
return sFilePath; 3[m~-8
} @r"\bBi
mqSVd^
}lZEdF9GhG
public void setSFilePath(String value) %|-N{>wKy
{ |XyX%5p*
sFilePath = value; h<.5:a
} ;UdM8+^/V]
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public String getSFileName() s*uA3}j
{ q;{(o2g
return sFileName; {##G.n\~
} K~(RV4oF8B
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g)hEzL0k
public void setSFileName(String value) v\xl?F
{ $>rt0LOF
sFileName = value; 3.&BhLT
} Iiy5;:CX:q
9{Hs1MD[
zJDHDr
public int getNSplitter() -E-#@s
{ 4n,&,R r#
return nSplitter; K?.~}82c
} &PMQ]B
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public void setNSplitter(int nCount) Fis!MMh.$
{ ~ 'ZwD/!e
nSplitter = nCount; *|rdR2R!
} .UK0bxoa
} WK%cbFq(
XYcZ;Z9:
;dIk$_FN
/* g]~vZj
**Utility.java v({O*OR
*/ %i9S"
package NetFox; !6/UwPs
{vu\qXmMv
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public class Utility { ?9 huuJs7
AR|4^
91R#/i
public Utility() YidcVlOsO
{ Wa;N(zw0h
vC]X>P5Px
*byUqY3(
} i?T-6{3I
Q 3WD!Z8y
//线程睡眠 +d, ~h_7!
public static void sleep(int nSecond) VDxm|7
{ {;$oC4
try{ k+J3Kl09hM
Thread.sleep(nSecond); geQ!}zXWi
} l*ltS(?
catch(Exception e) ,TBOEu."4
{ _c>iux;
e.printStackTrace (); BM :x`JY
} N*gJu
} I~7iIUD
f2gtz{r
//日志 AG(6.
public static void log(String sMsg) f_k'@e{
{ [-(^>Y
System.err.println(sMsg); -%fQr5
} 4"&-a1N
(\:Rnl
4Kj.o
public static void log(int sMsg) rPk|2l,E,3
{ }Rh\JDiQ
System.err.println(sMsg); z5@XFaQ
} D]~K-[V?l
} rWht},-|1
&8IBf8
^J^,@Hf_
/* QE]'Dc%
**TestMethod.java Ts!'>_<Je
*/ (cj9xROx
package NetFox; 6Zi{gx
juEPUsE
Q<sqlh!h
public class TestMethod { J2O,wb)U
KjGu !B
a>j}@8[J
public TestMethod() ]B/>=t"E
{ ///xx/weblogic60b2_win.exe _H$Lu4b)N
try{ YZ~MByu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6A"$9sj6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GvVkb=="
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7}iv+rQ
fileFetch.start(); J;& y?%{@5
} ::Zo` vP
catch(Exception e){e.printStackTrace ();} /WQ.,a
"#C2+SKM1
3Gs\Q{O:
} 3?o4
e!VtDJDS
<+QdBp'd;
public static void main(String[] args) GDLw_usV
{ xvl$,\iqE
new TestMethod(); v,")XPY
} 8maWF.xq
} 5FZw (E
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