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)); crdp`}}
} [$b\#{shtP
for(int i=0;i<nEndPos.length-1;i++) R0!qweGi@
{ P6cc8x9g(
nEndPos = nStartPos[i+1]; KoPhPH
} %7*Y@k-)o
nEndPos[nEndPos.length-1] = nFileLength; NhDM h8=$^
} ^,.G<2Kx&
} x>yeF,q1
I3ZbHb-)_,
)=)=]|3
//启动子线程 "T_OLegdK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]%K 8
for(int i=0;i<nStartPos.length;i++) =5-|H;da
{ !MiH^wP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8I'Am"bc\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mfNYN4Um6
nStartPos,nEndPos,i); )@]Y1r4U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *&vySyt
fileSplitterFetch.start(); = yH#Iil
} kM`!'0kt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DNy1} 3wg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Tmo+I4qoL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x>@+lV'O
nEndPos = " + nFileLength); &@dWd
// fileSplitterFetch[nPos.length-1].start(); DfCo=
(!nhU
`euk&]/^.)
//等待子线程结束 Q\DD^Pbq
//int count = 0; o9:GKc
//是否结束while循环 hkO)q|1
boolean breakWhile = false; dD2N!umW
[]{g9CO
QcQ:hHF
while(!bStop) 7x%0^~/n
{ 9xvE?8;M#
write_nPos(); Xjal6e)[
Utility.sleep(500); fU+A~oL%I
breakWhile = true; ZcXqH7`r
%EuXL% B
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for(int i=0;i<nStartPos.length;i++) T#1>pED
{ }31z 35
if(!fileSplitterFetch.bDownOver) %NbhR(
{ 1u\fLAXn
breakWhile = false; iaR^]|7_
break; KUfk5Y
} K/ q:aMq
} -IR9^)
if(breakWhile) Te"<.0~1
break; ,/\%-u? 1x
wovWEtVBU
Pl=X<Bp
//count++; A$RN7#
//if(count>4) ku*|?uF
// siteStop(); }6P]32d
} "[=Ee[/
zxCxGT\;
Web|\CH
System.err.println("文件下载结束！"); y8fsveX
} ?yh}/T\qp
catch(Exception e){e.printStackTrace ();} EbqcV\Kb
} z({hiVs
HF3f)}l$
^e+a
//获得文件长度 %vBhLaE
public long getFileSize() ?McQr1
{ N/GQt\tV<
int nFileLength = -1; >0l"P"]
try{ +f[ED4E>'(
URL url = new URL(siteInfoBean.getSSiteURL()); ngGO0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |ae975
httpConnection.setRequestProperty("User-Agent","NetFox"); qc-mGmomL
j2 !3rI
LdB($4,
int responseCode=httpConnection.getResponseCode(); \e`~i@) ~Z
if(responseCode>=400) Y"KE7>Jf
{ Z{H5oUk
processErrorCode(responseCode); s`#(
return -2; //-2 represent access is error csfgJ^n
} f3UXCp
`c'W-O/
><=gV~7lx
String sHeader; >CkjUZu]&
HI@syFaJM
Q);n<Z:X~
for(int i=1;;i++) &7_Qd4=08w
{ E#s)52z=B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +}-@@,
//Utility.log(in.readLine()); oTT7M`P3h
sHeader=httpConnection.getHeaderFieldKey(i); @JRNb=?a
if(sHeader!=null) oHs2L-G
{ \cCV6A[
if(sHeader.equals("Content-Length")) R<V!%rL;;
{ san,|yrMn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hI(SOsKs
break; ?Mee 6
} Q~Z=(rP20
} 'ky b\q
else r/*=%~*
break; KWWa&[ev)
} t3+Py7qv
} bb d.
catch(IOException e){e.printStackTrace ();} PdVfO8-
catch(Exception e){e.printStackTrace ();} mJM_2Ab
,()0'h}n
BT@r!>Nl
Utility.log(nFileLength); H}:LQ~_2
f#Xyoa%
^OErq&`u
return nFileLength; 5xOvY
} _$>pw<
EJ`T$JD
nB] >!q
//保存下载信息（文件指针位置） 72veLB
private void write_nPos() & =/
{ 4GB7A]^E
try{ ?^j^K-rx
output = new DataOutputStream(new FileOutputStream(tmpFile)); PpsIhMq@
output.writeInt(nStartPos.length); Dn>%%K@0
for(int i=0;i<nStartPos.length;i++) V:G>G'Eh0
{ zuJtpMn
// output.writeLong(nPos); { m|pl
output.writeLong(fileSplitterFetch.nStartPos); ] 7 _`]7p
output.writeLong(fileSplitterFetch.nEndPos); z(\4M==2O
} |A8/FU2{
output.close(); cr;g5C V
} KeNL0_Pw
catch(IOException e){e.printStackTrace ();} `|Or{ih
catch(Exception e){e.printStackTrace ();} LbtX0^
} A0%}v*
t&9A ]<n%,
A 8 vbQ
//读取保存的下载信息（文件指针位置） ;us%/kOR
private void read_nPos() Nl')l"
{ kapC%/6"
try{ 4Bl{WyMJ|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G/v/+oX
int nCount = input.readInt(); Pm$q]A~
nStartPos = new long[nCount]; ~n/ $
nEndPos = new long[nCount]; [{r}u
for(int i=0;i<nStartPos.length;i++) V_Wwrhua
{ V i&*&"q
nStartPos = input.readLong(); F_bF
nEndPos = input.readLong(); +78CvjG
} =~I-]4
input.close(); S"wg2X<
} .IJ_jt-^d
catch(IOException e){e.printStackTrace ();} -rKO )}
catch(Exception e){e.printStackTrace ();} zm,@]!wI
} :{q"G#
V)P&Zw
vLxQ *50v$
private void processErrorCode(int nErrorCode) R1Ye<R!Q
{ Iyo@r%I
System.err.println("Error Code : " + nErrorCode); -8N|xQ378
} Z#.f&K )xX
w{dIFvQ"$
,/O[=9l36R
//停止文件下载 8t=(,^c
public void siteStop() +-B^Z On
{ +ki{H}G21
bStop = true; }KD;0t4
for(int i=0;i<nStartPos.length;i++) ~r{5`;c
fileSplitterFetch.splitterStop(); =:SN1#G3n
LJVG~Yeo
ESoAzo,u
} }CxvT`/
} O@iu aeEW
//负责部分文件的抓取 )+H[kiN
**FileSplitterFetch.java 3DaQo0N
*/ 1.q_f<U
package NetFox; s s 3t
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e5Mln!.o
import java.io.*; _j>;ipTb+
import java.net.*; PIXL6
xug)aE
dO7;}>F$n
public class FileSplitterFetch extends Thread { 8q)=
gw _$
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String sURL; //File URL [i]r-|_K
long nStartPos; //File Snippet Start Position YK{a
long nEndPos; //File Snippet End Position UhmTr[&
int nThreadID; //Thread's ID u-"c0@
boolean bDownOver = false; //Downing is over AOrHU M[I
boolean bStop = false; //Stop identical k n8N,,+
FileAccessI fileAccessI = null; //File Access interface *V(Fn-6(
zhB">j8j
0|D&"/.R#!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l.nH?kK<
{ *5,c Rz
this.sURL = sURL; @/%{15s.
this.nStartPos = nStart; woq)\;CK
this.nEndPos = nEnd; %]p6Kn/>
nThreadID = id; xv7"WFb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wcDjg&:=ml
} kcB+_
Lv1{k\aw
>6Lm9&}
public void run() >NV=LOO
{ N]5m(@h
while(nStartPos < nEndPos && !bStop) x O7IzqY
{ 8Z85D
HI&kP+,y
(P6vOo
try{ Hoz56y
URL url = new URL(sURL); 0"[`>K~7a8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c#xP91.m
httpConnection.setRequestProperty("User-Agent","NetFox"); OuIv e>8
String sProperty = "bytes="+nStartPos+"-"; `#IcxweA
httpConnection.setRequestProperty("RANGE",sProperty); [;O^[Iybf:
Utility.log(sProperty); I_ "Z:v{
lu UYo
?a/n<V '
InputStream input = httpConnection.getInputStream(); @kD8^,(oH
//logResponseHead(httpConnection); G%TL/Z40
&d`^E6#
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byte[] b = new byte[1024]; n<V1|X
int nRead; )"O{D`uX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) POU}/e!Ua
{ nq`q[KV:
nStartPos += fileAccessI.write(b,0,nRead); INMP"1
//if(nThreadID == 1) dYOF2si~%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p*;Qz
} %hT4qzJj
zREJ#r
:Eh'(
Utility.log("Thread " + nThreadID + " is over!"); jOtX 60;
bDownOver = true; m[2'd
//nPos = fileAccessI.write (b,0,nRead); nJ3vi}`
} <6N_at3
catch(Exception e){e.printStackTrace ();} }WP-W
} p4/$EPt)lY
} zJ& b|L
P6?0r_Y
w4MwD?i]R
//打印回应的头信息 K^i"9D)A
public void logResponseHead(HttpURLConnection con) Go+[uY^
{ 9F_6}.O
for(int i=1;;i++) K%,$ V,#
{ m7 XjP2
String header=con.getHeaderFieldKey(i); f?0s &Xo
if(header!=null) QdDtvJLf
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a20w,
Utility.log(header+" : "+con.getHeaderField(header)); j|'R$|
else t;Wotfc[#0
break; y' tRANxQ
} A_r<QYq0|
} r#~K[qb
XNmQ?`.2'
+0#JnqH"
public void splitterStop() yU`:IMz
{ }V^e7d
bStop = true; <%,'$^'DS
} SgSk!lj
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Hcl"T1N*
} nu 7lh6o=
9.Ap~Ay.
vw rRZ"2
/* ^]rxhpS
**FileAccess.java }GRMZh_8
*//文件访问(定位，写) /VtlG+dLl
package NetFox; y\_wWE
import java.io.*; +2O=s<fp
6:RMU
?cBO6^
public class FileAccessI implements Serializable{ "8t\MKt(
)H+h;U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &l!$Sw-u;
RandomAccessFile oSavedFile; Y2vj}9jK
long nPos; Sf5]=F-w
D% @KRcp^b
:C}Hy
public FileAccessI() throws IOException nhT;b,G.Z
{ rys<-i(
this("",0); As}eUm)B5c
} WJcVQMs
V#H8d_V
n'3u]~7^
public FileAccessI(String sName,long nPos) throws IOException q4k`)?k9
{ /yt7#!tm+
oSavedFile = new RandomAccessFile(sName,"rw"); x,-S1[#X;
this.nPos = nPos; _jDS"
oSavedFile.seek(nPos); 4a 4N C
} cI3KB-lM#
0&B:\
Ut':$l=
public synchronized int write(byte[] b,int nStart,int nLen) IhR;YM[K
{ n1XJuc~
int n = -1; >;qAj!'
try{ x)}.@\&%
oSavedFile.write(b,nStart,nLen); p9X{E%A<:
n = nLen; "kb[}r4?
} wmV7g7t6
catch(IOException e) 7=3'PfS
{ 9Gh:s6
e.printStackTrace (); wqnrN6$jf
} qQN|\u+co
)t#>fnN
e};\"^HH
return n; !&(^R<-id
} 4 *n4P
C(Cuk4K
wjzR 8g0bQ
} 57|RE5]|!
KT3n-Y-,
BT*z^ZH
/* w|,BTM:e
**SiteInfoBean.java q 3nF\Me0
*/ qrr[QEFW
package NetFox; N\{{:<Cp\
/gH[|d
xfzGixA
public class SiteInfoBean { zNo>V8B(
uN;]Fv@Z
"/kTEp
private String sSiteURL; //Site's URL ;h~v,h
private String sFilePath; //Saved File's Path Pd8zdzf{
private String sFileName; //Saved File's Name xJ rKH
private int nSplitter; //Count of Splited Downloading File 5>x?2rp
."u DM<
bXNM.K
public SiteInfoBean() o"gtWAGH
{//nSplitter的缺省值为5 7[I%UP
//default value of nSplitter is 5 #d*)W3e2{
this("","","",5); B:]%Iu|
} nj4G8/U-q
yx\I&\i
y#iQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &_dM2lj{
{ MhL>6rn
sSiteURL= sURL; f&2f8@
sFilePath = sPath; igO,Ge8}
sFileName = sName; L ]Y6/Q
this.nSplitter = nSpiltter; <|>7?#s2=
|r<#>~*
G$oi>zt3
} R14&V1 tZ
W3l[a^1d
$%U}k=-
public String getSSiteURL() tE>FL
{ I'D3~UIf
return sSiteURL; D~inR3(}
} fq1w <e
QM!UMqdj
M"mvPr9
public void setSSiteURL(String value) "eoPG#]&
{ Z9mI%sC[(
sSiteURL = value; t<`wK8)
} :Gz$(!j1.'
4FnePi~i
.aL%}`8l?
public String getSFilePath() ym p*:lH(
{ DmoY],9I+p
return sFilePath; 4Zjd g`
} 4PC'7V=S
0#c-qy
Y&VypZ"G>
public void setSFilePath(String value) "=s dn
{ HJr*\%D}1
sFilePath = value; Ev#,}l+
} I9TNUZq('
2+|r*2_glo
}+ W5Snx
public String getSFileName() ILNghtm-
{ 4YOLy\"S
return sFileName; r& RJ'z
} {3Gj rE
Q0PqyobD
@8YuMD;
public void setSFileName(String value) ,0L< wa
{ %[,^2s
sFileName = value; q9(O=7O]-
} J_ h\tM
p<VW;1bt5
9X{aU)"omQ
public int getNSplitter() STB=#z
{ ^Sr`)vP
return nSplitter; {Z|.-~W
} e~weYGK
*K\/5Fzl
VL<)d-
public void setNSplitter(int nCount) Pz+8u&~p
{ 7b T5-=.
nSplitter = nCount; .,x08M
} D`.CXFI+U
} : C;=<$
6i\b&
r jL%M';
/* !/$BXUrd
**Utility.java _"F(w"|
*/ F+AShh
package NetFox; F:M3^I
YKUs>tQ!
<OW` )0UX
public class Utility { {{=7mbc
37!}8
Xf9VW}`*8
public Utility() z0Gh |N@)
{ Q_1EAxt
B69NL
s6).?oE
} <H E'5b
#, vN
//线程睡眠 F{f "xM
public static void sleep(int nSecond) Jb {m
{ >1mCjP
try{ M* QqiE
Thread.sleep(nSecond); v?h#Ym3e<
} @eT!v{o
catch(Exception e) g >-iBxml
{ !OWV* v2
e.printStackTrace (); 8X*6i-j5E
} **0Y*Ax@
} OjeM#s#N!
>&U]j*'4
//日志 FJ>| l#nO
public static void log(String sMsg) )Hlr 09t=]
{ w},k~5U^s
System.err.println(sMsg); 8u;l<^<
} |n67!1
%t%+;(M9
"PJ@Q9n__
public static void log(int sMsg) t]"3vE>
{ cKK 1$x
System.err.println(sMsg); }e9:2
} }L@!TWR-Qu
} 0V`0="rQ
]eP&r?B
k9WihejS
/* yHk/8
**TestMethod.java `Nu3s<O7CF
*/ o& $Fc8bH
package NetFox; jcOxtDTSW
Cq/*/jBM
*wyaBV?*K
public class TestMethod { $xlI"-(
) <^9`
~n|*-rca
public TestMethod() 6#.z:_
{ ///xx/weblogic60b2_win.exe <q%buyQna
try{ JyYg)f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m[Px|A5{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t#}/VnSQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); &FIPEe#n
fileFetch.start(); KS1Z&~4
} p@NE^aMn
catch(Exception e){e.printStackTrace ();} &D>e>]E|P
VL&E2^*E
@B*?owba>
} W<u63P
.z7F58
;0P2nc:U~
public static void main(String[] args) .& B_\*
{ 5A Vo#}&\
new TestMethod(); S;a{wYF6v
} S;MS,R
} [9~Bau
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