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)); b.,$# D{p
} 'ucGt
for(int i=0;i<nEndPos.length-1;i++) b_l.QKk
{ uegb;m
nEndPos = nStartPos[i+1]; =<>pKQ)[
} Z]p8IH%~92
nEndPos[nEndPos.length-1] = nFileLength; Q~h6J*
} N[]U%9[=2F
} pB[%:w/@l:
2!{N[*)
tw]/,>\G
//启动子线程 a2[8wv1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U* 4{"
for(int i=0;i<nStartPos.length;i++) u8xk]:%
{ yIlV[_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v<%]XHN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 17|@f
nStartPos,nEndPos,i); BjwMb&a;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7<fL[2-
fileSplitterFetch.start(); 6/VNuQ_#
} Ko]QCLL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >@z d\}@W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #i@ACAgn;6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Th_Q owk
nEndPos = " + nFileLength); *ZX!EjICk
// fileSplitterFetch[nPos.length-1].start(); dEL3?-;'
TLXhE(o|o
7:#
//等待子线程结束 jGJ.Pvc>i
//int count = 0; 2\DTJ`Y,
//是否结束while循环 zUNH8=U
boolean breakWhile = false; r(pwOOx
5XI;<^n2
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while(!bStop) VjC*(6<Gj
{ .@fK;/OuC
write_nPos(); };i&a%I|
Utility.sleep(500); z7| s%&
breakWhile = true; P\Ai|"=&]
m*\B2\2gJ
Cc@=?
for(int i=0;i<nStartPos.length;i++) =U=e?AOG2
{ 83\o(
if(!fileSplitterFetch.bDownOver) bl$+8!~
{ 71JM [2
breakWhile = false; lv=yz\
break; BhOXXa{B
} @47[vhE
} tZdwy>;
if(breakWhile) AD~~e% s=
break; 9Q,Msl4n
zJz82jMm
-q'xC:m
//count++; pESB Il
//if(count>4) LDT'FwMjy
// siteStop(); XRClBTKF
} GI.=\s
E!rgR5Bd
v$JhC'
System.err.println("文件下载结束！"); =sFLzAu8
} =CqZ$
catch(Exception e){e.printStackTrace ();} (?W[#.=7
} 7iijATc
SW; %2
zt3y5'Nk
//获得文件长度 HzdyfZ!jR
public long getFileSize() n,l{1 q
{ hO?RsYJ.F
int nFileLength = -1; S!oG|%VuB#
try{ .$]%gjIBCl
URL url = new URL(siteInfoBean.getSSiteURL()); d(t$riFX}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2N/4.
httpConnection.setRequestProperty("User-Agent","NetFox"); HAca'!p
m,|)$R
K (!+l
int responseCode=httpConnection.getResponseCode(); 0D.qc8/V4.
if(responseCode>=400) bf*VY&S-T
{ #)7THx/=
processErrorCode(responseCode); \2U FJ
return -2; //-2 represent access is error FG@ ')N!g
} r@)_>(
tgpg
~jOn)jBRZ
String sHeader; ~k[mowz0
OF_g0Zu
zQ>|`0&8
for(int i=1;;i++) rAwuWM@BIg
{ YEiQ`sYKG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !kG2$/lR
//Utility.log(in.readLine()); QKVFH:"3
sHeader=httpConnection.getHeaderFieldKey(i); GB&^<@
if(sHeader!=null) !M*$pQi}
{ xZc].l6
if(sHeader.equals("Content-Length")) WETnrA"N
{ W+5<=jXFB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xC}9W6
break; c7R<5f
} r&0IhE
} I|eYeJ3
else E/5/5'gBJO
break; ymo].
} Wm#F~<$
} 8H7=vk+
catch(IOException e){e.printStackTrace ();} w;=g$Bn
catch(Exception e){e.printStackTrace ();} [,?5}'we
*+rWn*L
_7=LSf,9
Utility.log(nFileLength); tOT(!yz
@en*JxIM
*MD\YFXR
return nFileLength; k[<Uxh%
} -:~"c@D
[==x4Nb
)z=L^ot
//保存下载信息（文件指针位置） <Y"h2#M"
private void write_nPos() t,,W{M|E(
{ !U[/P6 +0
try{ d,+a}eTP'
output = new DataOutputStream(new FileOutputStream(tmpFile)); HpGI\s
output.writeInt(nStartPos.length); 7%)KB4(\_
for(int i=0;i<nStartPos.length;i++) @{LD_>R
{ e,8[fp-7
// output.writeLong(nPos); bg/a5$t
output.writeLong(fileSplitterFetch.nStartPos); "fN=Y$G
output.writeLong(fileSplitterFetch.nEndPos); \\iX9-aI<
} x3tos!Y
output.close(); ,C;%AS/
} dW#T1mB
catch(IOException e){e.printStackTrace ();} 5e|yW0o
catch(Exception e){e.printStackTrace ();} =tQ^t4_
} Mv_-JE9#>o
ttfCiP$
S!6 ? b5
//读取保存的下载信息（文件指针位置） H7?Sd(U
private void read_nPos() PW QRy
{ #dhce0m
try{ ^SvGSxi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /L^pU-}Z0
int nCount = input.readInt(); k^Qd%;bdF
nStartPos = new long[nCount]; U-:"Wx%G
nEndPos = new long[nCount]; -I'Jm=q3]
for(int i=0;i<nStartPos.length;i++) \PL0-.t,
{ }/J<#}t
nStartPos = input.readLong(); mbZn[D_zi
nEndPos = input.readLong(); 5iZx -M
} 8{DW$ZtR
input.close(); *|({(aZ
} 2e^6Od!Y?
catch(IOException e){e.printStackTrace ();} vf0 fa46
catch(Exception e){e.printStackTrace ();} b"pN;v
} +. tcEbFL
{&uN q^Ch
2ut)m\)/)
private void processErrorCode(int nErrorCode) RXw }Tb/D8
{ 4L<;z'
System.err.println("Error Code : " + nErrorCode); ?%ei+
} (q}{;
,Q,3^v-
@B9O*x+n:
//停止文件下载 63HtZ=hO7
public void siteStop() -7u_\XFk
{ KMP[Ledr
bStop = true; hka`STK{
for(int i=0;i<nStartPos.length;i++) k2:mIp\
fileSplitterFetch.splitterStop(); zb. ^p X
CF]#0*MI
Z)!#+m83>-
} xp%LXxj
} iD)P6"
//负责部分文件的抓取 R47tg&k6[
**FileSplitterFetch.java >uR;^B5m
*/ tvOyT6]
package NetFox; d;v<rw
9)J)r\
paZcTC
import java.io.*; C]M{
import java.net.*; ~}g)N
,+!|~1
j$Vtd&
public class FileSplitterFetch extends Thread { \OVw
UQO?hZ!y/.
PJ2m4ulY
String sURL; //File URL TlpQ9T
long nStartPos; //File Snippet Start Position !yu-MpeG
long nEndPos; //File Snippet End Position 7'RU\0QG
int nThreadID; //Thread's ID \:>eZl?
boolean bDownOver = false; //Downing is over uO4R5F|tL
boolean bStop = false; //Stop identical 9&Ny;oy#6
FileAccessI fileAccessI = null; //File Access interface $: qrh66
dF'oZQz
F32U;fp3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `q+Ug
{ /JmWiBQIn
this.sURL = sURL; #Kt5+"+7
this.nStartPos = nStart; 3$PGLM
this.nEndPos = nEnd; ]]/p.#oD,
nThreadID = id; UB7C,:"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q#}c5TjVr
} 2YpJ4.
=z9FjK
I ka V g L
public void run() .1h1J
{ m-R`(
while(nStartPos < nEndPos && !bStop) O>>%lr|
{ <v$yXA
iQz c$y^,9
J#Agk^Y 5
try{ 1VB{dgr
URL url = new URL(sURL); ^\FOMGai
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dgW/5g
httpConnection.setRequestProperty("User-Agent","NetFox"); zN>tSdNkI-
String sProperty = "bytes="+nStartPos+"-"; no8FSqLUS~
httpConnection.setRequestProperty("RANGE",sProperty); y-vQ4G5F|
Utility.log(sProperty); <26Jif:
RaAvPIJa |
Kr74|W=
InputStream input = httpConnection.getInputStream(); rM)-$dZ
//logResponseHead(httpConnection); tkf^sGgNO
="s>lI-1a
~4u[\&Sh
byte[] b = new byte[1024]; 6"|+\
int nRead; )X5en=[)O
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v9l|MI15V
{ {WN??eys,
nStartPos += fileAccessI.write(b,0,nRead); t"FB}%G
//if(nThreadID == 1) VB@M=ShKK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A9ru]|?
} @1+({u#B
$s!2D"wl n
Lb%:u5X\D@
Utility.log("Thread " + nThreadID + " is over!"); zn/b\X/
bDownOver = true; PVX23y;
//nPos = fileAccessI.write (b,0,nRead); 9vJ'9Z2\
} 'Y:ZWac,
catch(Exception e){e.printStackTrace ();} j$}W%ibj
} p|VgtQ/)%
} 992cy2,Fb
.dl4f"k
hT[w" &3
//打印回应的头信息 ^y3snuLtE
public void logResponseHead(HttpURLConnection con) F;<cG`|Rx
{ ljw>[wNv
for(int i=1;;i++) h . R bdG
{ 1bpjj'2%x
String header=con.getHeaderFieldKey(i); E:S (v
if(header!=null) ("ulL5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t.= 1<Ed
Utility.log(header+" : "+con.getHeaderField(header)); z.]
else fv?vfI+m
break; GHR,KB7 xM
} e$=0.GWT
} 7~7_T#dTh
yfCdK-9+B
Q:sw*7"F
public void splitterStop() V~_aM@q1
{ q8P$Md-=b1
bStop = true; =U_O;NC
} eBxOa
DW.vu%j^[
pZO`18z
} ,pMH`
H3qM8_GUA
w8>
/* 9|9Hk1
**FileAccess.java fC^POLn[f
*//文件访问(定位，写) `dK%I U
package NetFox; '}.Z' %;
import java.io.*; cR"?EQ] `N
k^v P|*eu
E4dN,^_ F!
public class FileAccessI implements Serializable{ S1oP_A[|
!e0~|8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gdkQ h_\
RandomAccessFile oSavedFile; 2#?qey
long nPos; <u%&@G$F>
j65qIw_Z
O0Sk?uJ<
public FileAccessI() throws IOException *aT\V64
{ UjrML
this("",0); i$:QOMA
} |H7f@b]Sk
cas5
>^q7:x\
public FileAccessI(String sName,long nPos) throws IOException SWrP0Qjc
{ cczV}m2)
oSavedFile = new RandomAccessFile(sName,"rw"); V'jvI
this.nPos = nPos; ygn]f*;?kw
oSavedFile.seek(nPos); ,U^V]jC
} >p;cbp[ht
Wz]ny3K[.
cgevP`*]
public synchronized int write(byte[] b,int nStart,int nLen) ^a+H`RD
{ C}>Pn{wY9
int n = -1; ql_GN[c/
try{ zEYT,l
oSavedFile.write(b,nStart,nLen); "{F e
n = nLen; EmO{lCENk
} mM6X0aM
catch(IOException e) 'ZboLoS*-
{ ltH?Ew<]
e.printStackTrace (); ]> dCt<
} e0; KmQjG
:497]c3#5C
;#jE??E/:
return n; v@^P4cu;
} PUJkC
y6C3u5`
O h{>xg
} 8+yCP_Y4
^vA"3Ixb!
(o5^@aDr
/* EFqYEDXW
**SiteInfoBean.java Z\9DtvV
*/ 0 P]+/
package NetFox; R@[gkj
8,^2'dK34
EO: VH
public class SiteInfoBean { z +NwGVk3
E[8R )xC@
rOyKugHe
private String sSiteURL; //Site's URL <T|?`;K
private String sFilePath; //Saved File's Path e*?@6E
private String sFileName; //Saved File's Name A0f98?j^
private int nSplitter; //Count of Splited Downloading File ;?K>dWf3f
:*6#(MX
3 J!J#
public SiteInfoBean() ^0fe:ac;
{//nSplitter的缺省值为5 N" =$S|Gs
//default value of nSplitter is 5 \lBY4j+;
this("","","",5); % r>v^1Vo
} vkgAI<
>o_cf*nx
zHu w[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lv=rL
{ n=8DC&
sSiteURL= sURL; li7"{+ct
sFilePath = sPath; $FM:8^
sFileName = sName; ~M?^T$5
this.nSplitter = nSpiltter; D]StDOmM
NB=!1;^J
Bl1^\[#
} *< ?~
Hph$Z1{
C=zc6C,
public String getSSiteURL() Vu1swq)l
{ cI/Puh^3
return sSiteURL; L2}p<?f
} tB/'3#o
g* DBW,
;cD&qheDV
public void setSSiteURL(String value) 9tBE=L=
{ d:{#Dk#
sSiteURL = value; f C_H0h3
} t}x^*I$*
|:b!e
8=Aoj%l#
public String getSFilePath() FL?Ndy"I
{ #y>q)Ph
return sFilePath; ]7:*A7/!.
} + )lkHv$R
v~`'!N8
,%4~ulKMn
public void setSFilePath(String value) *DS>#x@3*i
{ gl>%ADOB@
sFilePath = value; t^5xq8w8
} 8;GuJP\
E*G{V j
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public String getSFileName() Q8?:L<A
{ >#EOCo
return sFileName; (_Ky'.
} HBiUp$(mB
ka?EXF:
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public void setSFileName(String value) IEeh9:Km
{ rPXy(d1<`S
sFileName = value; Qoom[@$
} pZV=Co3!I
cZl/8?dj}
@l %x;`E
public int getNSplitter() E9~}%&
{ klxNGxWAX
return nSplitter; \Jm^XXgS
} #CTeZ/g
n1PV/ Z
~tB#Q6`nB
public void setNSplitter(int nCount) Un^3%=;
{ )=5,S~IT
nSplitter = nCount; `g^bQx
} . l-eJ
} D V=xqC6}
{2T;^+KE
Qa@] sWcM
/* i(an]%'v
**Utility.java kJk6lPSqi7
*/ b/6!>qMMk%
package NetFox; v!6IH
&at>sQ'
Rg\D-F6:
public class Utility { 2f0qfF
fp?cb2'7
N-YCOSUu
public Utility() Ngw/H)<c
{ kj/v$m
!~fy".|x
,lb >
} 5j>olz=n}
<RJ+f-
//线程睡眠 l dw!G/
public static void sleep(int nSecond) ykD-L^}
{ "5b4fQ;x
try{ qc"PTv0q
Thread.sleep(nSecond); bmI6OIWl
} \%Lj !\
catch(Exception e) %6cbHH
{ ;X%8I$Ba,
e.printStackTrace (); t-?#x
} h{VdW}g
} Xz\X 8I
{Y1&GO;
//日志 35n'sVn
public static void log(String sMsg) }.N~jx0R
{ ~*hCTqHvN
System.err.println(sMsg); U$Od)
} L|Bjw3K&D
L!0}&i;u~5
Tl L\&n.$
public static void log(int sMsg) K96N{"{iI%
{ :Ny^-4-N
System.err.println(sMsg); UY^TTRrH
} =k##*%
} vY);7
z yrjb8
cQrXrij;!
/* I|. <
**TestMethod.java hr`,s!0Y
*/ =+w/t9I[
package NetFox; cf%aOHYI*
V?"1&m&E
7[:?VXQ
public class TestMethod { F0ylJ /E
2[i(XG{/
cK\'D
public TestMethod() -FQc_k?VF
{ ///xx/weblogic60b2_win.exe +Ou<-EQV
try{ TUq ,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qJ[wVNHh!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~toR)=Yv
SiteFileFetch fileFetch = new SiteFileFetch(bean); A9y@v{txN
fileFetch.start(); J~)JsAXAI
} 7ea%mg\
catch(Exception e){e.printStackTrace ();} T[kS;-x
Q}|0
TGuCIc0B{
} 85BB{T;
q@i.4>x
8=u88?Bh
public static void main(String[] args) J|CCTXT
{ lcXo>
new TestMethod(); j-zWckT{
} z`sW5K(A
} r=#v@]zB
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