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)); U9N}6a=
} %NAz(B
for(int i=0;i<nEndPos.length-1;i++) @Sv ?Ar
{ :'rXu6c-
nEndPos = nStartPos[i+1]; o oS4F1ta
} ' !_44
nEndPos[nEndPos.length-1] = nFileLength; U}qW9X;o
} M_XZOlW5
} !-;Me&"I=`
h.7 1O"N
MA1,;pv6
//启动子线程 8a05`ZdP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \<PX'mnO
for(int i=0;i<nStartPos.length;i++) @D60
{ 'wQ=b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sJ0y3)PQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), # =322bnO
nStartPos,nEndPos,i); zD?$O7 |ZK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }7C{:H2d
fileSplitterFetch.start(); zg5u
} riBT5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y.hrU*[J0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +"p",Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]XP[tLYY
nEndPos = " + nFileLength); L4[bm[x
// fileSplitterFetch[nPos.length-1].start(); {{ wVM:1
MK"Yt<e(o
Y{J/Oib
//等待子线程结束 "1[N;|xa
//int count = 0; ga,yFw
//是否结束while循环 +HfjnEbtBs
boolean breakWhile = false; ]T*{M
\ _i`=dx
(JM4W "7'
while(!bStop) 6dinC <[}
{ E?FPxs
write_nPos(); @*c+`5)_
Utility.sleep(500); x[>A'.m@)
breakWhile = true; eEU:
Q% dpGI
RL&*.r&
for(int i=0;i<nStartPos.length;i++) KlrKGmy,)
{ N.&K"J
if(!fileSplitterFetch.bDownOver) w1GCjD*y
{ iYnw?4Y
breakWhile = false; Y&&Y:+ V
break; ! 4s$93
} \XpPb{:>
} {$s:N&5
if(breakWhile) r]]Ke_s!
break; ~q1s4^J
@L~y%#
'17=1\Ss6;
//count++; ~pF'Qw"z|
//if(count>4) o+tY[UX
// siteStop(); [@\f 0R
} OsK=% aDpj
h`vM+,I
*wSl~J|ZM%
System.err.println("文件下载结束！"); y'+^ ME$H
} jf%Ydr}`
catch(Exception e){e.printStackTrace ();} k5ZwGJ#r
} =W4cWG?+
d[S!e`,iD
^X_%e|
//获得文件长度 W&*{j;e9%I
public long getFileSize() t4JGd)r
{ J,q:
int nFileLength = -1; prm
try{ ^L'K?o
URL url = new URL(siteInfoBean.getSSiteURL()); -jyD!(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nh+$'6yT%
httpConnection.setRequestProperty("User-Agent","NetFox"); b;}MA7=
t7~mW$}O
nY*ODL
int responseCode=httpConnection.getResponseCode(); +(P;4ZOmB
if(responseCode>=400) V3`*LU
{ "Srp/g]a
processErrorCode(responseCode); N7M^
return -2; //-2 represent access is error )q=1<V44d
} JRo{z{!O6
V,Gt5lL&/!
aI\VqOt]
String sHeader; -I|yi'
2N]y)S_<V
Ny~;"n
for(int i=1;;i++) TQEZ<B$
{ kNjbpCE\!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }5]NUxQ_
//Utility.log(in.readLine()); *in_Zt3
sHeader=httpConnection.getHeaderFieldKey(i); `#(4K4]1.
if(sHeader!=null) l,/5$JGnk
{ $@U`zy"Y
if(sHeader.equals("Content-Length")) tl4;2m3w
{ SMhT>dB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nBD7
break; 2?"9NQvz
} G?"1 z;
} x7*}4>|W,I
else \fKv+
break; SKS[Lf
} F0|T%!FB>%
} '2 )d9_ w
catch(IOException e){e.printStackTrace ();} c^=:]^
catch(Exception e){e.printStackTrace ();} 1XZ&X]
-p)HH@6a
NT-du$!u
Utility.log(nFileLength); pG4Hy$e
! [:K/
OC[a?#R1
return nFileLength; HKh)T$IZM
} pkT a^I
i@p?.%K{
d5i/:
//保存下载信息（文件指针位置） i'57|;?
private void write_nPos() F^w0TD8
{ Z2`e*c-[E
try{ MJD4#G
output = new DataOutputStream(new FileOutputStream(tmpFile)); NH?s
output.writeInt(nStartPos.length); :Ert57@l
for(int i=0;i<nStartPos.length;i++) <iMkHch
{ {<_}[} XY
// output.writeLong(nPos); I{2e0
output.writeLong(fileSplitterFetch.nStartPos); zJV4)
output.writeLong(fileSplitterFetch.nEndPos); ~<$8i}7
} G)putk@
output.close(); B]hZ4.B1
} '6aH*B:}*;
catch(IOException e){e.printStackTrace ();} 8^~ljf]6
catch(Exception e){e.printStackTrace ();} l >O]Cpt
} ybB}|4d&
Z>{8FzP.F
cg$~.ytPK
//读取保存的下载信息（文件指针位置） C{'c_wX
private void read_nPos() !^N/n5eoz
{ !#X^nlc
try{ 6^wiEnA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C :e 'wmA
int nCount = input.readInt(); 2z-&Ya Qu
nStartPos = new long[nCount]; YGNX+6Lz
nEndPos = new long[nCount]; zxj!ihs<
for(int i=0;i<nStartPos.length;i++) &,#VhT![
{ P"%/
nStartPos = input.readLong(); [oYe/<3
nEndPos = input.readLong(); \myj Y
} KL|B| u
input.close(); ?hwQY}
} )wGC=,
catch(IOException e){e.printStackTrace ();} q|j;dI&
catch(Exception e){e.printStackTrace ();} @!F9}n AP
} 7N""w5
NeWssSje
q=EQDHmh
private void processErrorCode(int nErrorCode) /bw-*
{ S-L6KA{
System.err.println("Error Code : " + nErrorCode); hQkmB|];5
} ";zl6g"
*JDc1$H0
2/bck)p=
//停止文件下载 UM#]olh
public void siteStop() B(>_.x#kv
{ AUN Tc3
bStop = true; F:H76O`8
for(int i=0;i<nStartPos.length;i++) p@^2.O+
fileSplitterFetch.splitterStop(); Y /wvn8~C
jRBx7|ON
QzS{2Y[OQ
} co*5NM^
} 5 Fd]3
//负责部分文件的抓取 k%LE"Q
**FileSplitterFetch.java ?r@ZTuq#
*/ mhs%b4'>
package NetFox; T^Z#x-Q
!KF;Z|_(I
-Zw"o>
import java.io.*; N[mOJa:
import java.net.*; F4PD3E_#
z=u4&x|xA
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public class FileSplitterFetch extends Thread { 11)~!in
ht=yzJ9Pr
=6 [!'K
String sURL; //File URL )XNcy"
long nStartPos; //File Snippet Start Position bM!`C|,[s
long nEndPos; //File Snippet End Position |l~ADEg
int nThreadID; //Thread's ID !O.B,
boolean bDownOver = false; //Downing is over Q/+a{m0f
boolean bStop = false; //Stop identical w"Z>F]YZ
FileAccessI fileAccessI = null; //File Access interface Uligr_c?
pu^1s#g8w
-ss2X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Wd%j;glG
{ 4@VX%5uy
this.sURL = sURL; kz??""G7/
this.nStartPos = nStart; bb<Vh2b>R
this.nEndPos = nEnd; T<ua0;7
nThreadID = id; y"]> Rr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U%#=d@?
} (z.Vwl5
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public void run() c.XLEjV|
{ @e slF
while(nStartPos < nEndPos && !bStop) I4)vJ0
{ Obd!
`W/6xm(X5;
'|+_~ZO*d
try{ =GpLlJ`-
URL url = new URL(sURL); PK~okz4b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EYQ!ELuF
httpConnection.setRequestProperty("User-Agent","NetFox"); mEqV&M1;7l
String sProperty = "bytes="+nStartPos+"-"; dxd}:L~z
httpConnection.setRequestProperty("RANGE",sProperty); y3xP~]n
Utility.log(sProperty); xq]&XlA:ug
ZBYmAD
j9,X.?Xvx
InputStream input = httpConnection.getInputStream(); |)lo<}{
//logResponseHead(httpConnection); Tu"yoF
m760K*:i\
T&h|sa(
byte[] b = new byte[1024]; 'R$~U?i8
int nRead; 0q3:"X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jVA xa|S
{ <ImeZ'L7
nStartPos += fileAccessI.write(b,0,nRead); qzG'Gz{{qu
//if(nThreadID == 1) :')<|(Zy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D?E5p.!A
} Wl,yznT
k82'gJ;MC=
8=e\^Q+
Utility.log("Thread " + nThreadID + " is over!"); ?@XO*|xkSk
bDownOver = true; *7Mrng
//nPos = fileAccessI.write (b,0,nRead); F%Xq}LMd
} (O&b:D/Y
catch(Exception e){e.printStackTrace ();} ;uJVY)7a
} \GkcK$Y
} ;Rt,"W)
9fV57
N0XGW_f
//打印回应的头信息 XR+2|o
public void logResponseHead(HttpURLConnection con) 9*x9sfCv9
{ &Y,Rm78
for(int i=1;;i++) X$xqu\t7
{ "47nc1T+n
String header=con.getHeaderFieldKey(i); 8=?I/9Xh
if(header!=null) -8TLnl~[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Di L@NU!$q
Utility.log(header+" : "+con.getHeaderField(header)); @tP,l$O&
else C2VZE~U+
break; 59)PJ0E
} ik]UzB
} sI.Ezuw
[~;9Mi.XL
c2y5[L7?
public void splitterStop() KSexG:Xb
{ +Gjy%JFp
bStop = true; ](O!6_'d
} 5-sxTp
F!Uk`[L
Q[k}_1sWs$
} 2qEy"DKu
:xA'X+d/'
l^SKd
/* AKHi$Bk
**FileAccess.java `fL$t0"
*//文件访问(定位，写) ,,6e }o6
package NetFox; 2#rF/!`^
import java.io.*; @-W)(9kZ|
1ptPey
.|rpj&>g
public class FileAccessI implements Serializable{ i#eb%9Mn
!]"T`^5,Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VJPt/Dy{
RandomAccessFile oSavedFile; }6o` in>M
long nPos; Bp b_y;E
\ET7
N (43+
public FileAccessI() throws IOException $V@IRBm
{ u6D>^qF}@'
this("",0); +4@EJRC
} }?H|9OS
\oaO7w,:"
:lcoSJ
public FileAccessI(String sName,long nPos) throws IOException y0z}[hZ
{ k<AnTboa
oSavedFile = new RandomAccessFile(sName,"rw"); UGAP$_j ]P
this.nPos = nPos; v_b%2;<1
oSavedFile.seek(nPos); O8M;q!)y
} X)'uTf0
<Nkj)`%5iK
;]'mx
public synchronized int write(byte[] b,int nStart,int nLen) p-;*K(#X
{ 0(64}T)
int n = -1; WJl&Vyl2FL
try{ ]r|X[9
oSavedFile.write(b,nStart,nLen); qi$6y?
n = nLen; /5SBLp}Sy
} uN'e~X6
catch(IOException e) @UX'(W
{ cE[4CCpy
e.printStackTrace (); O,hT< s "
} mhVSZhx|
zsWYV n]
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return n; Z?dz@d%C
} Ia[e7
JZ9w!)U
@/7tN3O
} (Y:5u}*Y
r 5:DIA!
QYDSE
/* Koo%mr
**SiteInfoBean.java L_Ff*
*/ &pV'/
package NetFox; r. :LZEr
A-qdTJP
'4ftclzL
public class SiteInfoBean { HW)> `
3D(/k%;)
>6KuZ_
private String sSiteURL; //Site's URL zXIVHC,"{
private String sFilePath; //Saved File's Path X=8y$Yy
private String sFileName; //Saved File's Name >2tYw,m
private int nSplitter; //Count of Splited Downloading File VMZ\9IwI
( hp 52Vse
!Qy%sY
public SiteInfoBean() r".*l?=
{//nSplitter的缺省值为5 pxDkf|*
//default value of nSplitter is 5 >;LXy
this("","","",5); K)QMxn
} scT,yNV
W9+H/T7!
p D-k<8|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \oA>%+]5
{ 8KiG(6*Q
sSiteURL= sURL; Cjc>0)f&.
sFilePath = sPath; .nl!KzO6g
sFileName = sName; Arc6d5Q
this.nSplitter = nSpiltter; >k }ea5+
?0*,x)t
OX-t#R`
} r~nD%H:}P
g0O~5.f
Pqu]?X
public String getSSiteURL() n@[_lNa4GD
{ Vsw]v
return sSiteURL; e ?sMOBPlv
} ^hiIMqY_{`
jlXzfDT
1cq"H/N
public void setSSiteURL(String value) &6wD
{ <hkSbJF
sSiteURL = value; g\%;b3"#
} =S+*=jA
oN({X/P2j
_@2}zT
public String getSFilePath() *hWpJEV
{ UI2TW)^2
return sFilePath; WVZ](D8Gc]
} GBeWF-`B
2S,N9(7
5ir Ffr
public void setSFilePath(String value) K-,4eq!
{ zbY2gq@?
sFilePath = value; fab.%$
} 3']a1\sy^
qtrN=c3x
00SYNG!
public String getSFileName() ]w,:T/Z}
{ r+:]lO
return sFileName; "%peYNZ&%
} f4 k
H2kib4^i
A4uKE"WE
public void setSFileName(String value) b!p]\B!
{ 4t 5i9+h
sFileName = value; Nwwn #+
} YuXCRw9p;
)d~{gPr.
t|PQ4g<
public int getNSplitter() q]scKWYI
{ jlxY|;gZ-0
return nSplitter; W{RZ@3ZY
} ]J1oY]2~
!MXn&&e1
whi#\>i
public void setNSplitter(int nCount) mO=A50_&,Q
{ Z)&!ZlM
nSplitter = nCount; s5/u>d
} !n7'TM'
} hv0bs8h
Wu~cy}\
&t~NR$@
/* $-)T
**Utility.java **V8a-@
*/ dAWB.#
package NetFox; ;9CbioO
m#Ydq(0+
<78*-Ob
public class Utility { S,Z~-j
{^D; ($lm
=,b6yV+$D
public Utility() J@o_-\@
{ `# U<'$
Cnr=1E=
9a2[_Wy
} 0QP=$X
})+iAxR
//线程睡眠 0GlQWRa
public static void sleep(int nSecond) 7W'&v+\
{ &S=Qu?H
try{ GrUpATIx
Thread.sleep(nSecond); AGl#f\_^
} ;hPVe_/
catch(Exception e) (mr*Thy`@
{ 0bpGPG's&
e.printStackTrace (); bY-koJo
} o~<jayqU
} IL`LIJ:O
>V?W_oM)
//日志 O{7rIy
public static void log(String sMsg) Jkv!]C
{ mGDy3R90
System.err.println(sMsg); 3@nIoN'z
} 2Wg:eh
!</U"P:L
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public static void log(int sMsg) * V7bALY
{ ?V}ub>J/=
System.err.println(sMsg); rK3KxG
} 9M^5<8:
} oxBTm|j7
CIui9XNU
CA1Jjm=
/* _Ss}dU9
**TestMethod.java kh@O_Q`j
*/ H | C3{9
package NetFox; a x)J!I18
9B![l=Gh
7Vk9{x$z
public class TestMethod { h oO847
2}7_Y6RS*
Pl!E$
public TestMethod() amq,^
{ ///xx/weblogic60b2_win.exe .Tm.M7
try{ ,cxe"U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E=8GSl/Jx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KWeE!f 7G
SiteFileFetch fileFetch = new SiteFileFetch(bean); DE7y\oO]
fileFetch.start(); H0 Zo.Np
} >Tjl?CS
catch(Exception e){e.printStackTrace ();} HY eCq9S
}t"K(oamm
O8A(OfX
} am!ssF5s
-+u}u=z%
.N>*+U>>P
public static void main(String[] args) ?(U;T!n
{ 4%zy$,|e
new TestMethod(); q6*i/"mN*
} 3.Yg3&"Z
} J+Fev.9>
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