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)); 8jd;JPz@\
} P `}zlml
for(int i=0;i<nEndPos.length-1;i++) 10<x.8fSP
{ -fwoTGlX
nEndPos = nStartPos[i+1]; C${Vg{g7a
} @R/07&lBR
nEndPos[nEndPos.length-1] = nFileLength; {sihus#Q
} QMa;Gy
} k. MUdU^
tBq nfv
pm*xb]8y
//启动子线程 #MX'^RZ>2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;> _$`
for(int i=0;i<nStartPos.length;i++) ORyE`h
{ NO|KVZ~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F~%]6^$w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [Sr,h0h6
nStartPos,nEndPos,i); 8YZbP5'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U=DmsnD,
fileSplitterFetch.start(); A )^`?m3
} GN ]cDik
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T&%ux=Jt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Kqp(%8mf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G;v8$)Zj
nEndPos = " + nFileLength); #33fGmd[
// fileSplitterFetch[nPos.length-1].start(); r"``QmM
%X4xv_o`f
WF1px%
//等待子线程结束 TD'L'm|2
//int count = 0; aGJC1x
//是否结束while循环 6l5:1|8b,!
boolean breakWhile = false; 'MEz|Z
*AoR==:ya
O4r0R1VQM
while(!bStop) zm]aU`j
{ /tP|b_7O
write_nPos(); BGOuDKz9C
Utility.sleep(500); v1BDP<qU2
breakWhile = true; jT8#C=a7
e\Y*F
mz@T
for(int i=0;i<nStartPos.length;i++) RIb4!!',c
{ )-0kb~;|
if(!fileSplitterFetch.bDownOver) B:gjAb}9T
{ /4a._@1h[y
breakWhile = false; JRSSn]pw
break; 19O,a#{KHf
} q#vQv5
} RA KFU
if(breakWhile) .q `Hjmg<
break; Xe<sJ.&Wf
rM .|1(u
u=/{cOJI6
//count++; Y%PwktQm
//if(count>4) &j4xgh9
// siteStop(); a=DcZ_M
} #0ETY\}ZD
S{;sUGcu
c0%"&a1]]V
System.err.println("文件下载结束！"); f0X_fm_q
} bn^{c
catch(Exception e){e.printStackTrace ();} NWM8[dI
} V n*
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O-LO/*5MI
//获得文件长度 ~-EOjX(X'E
public long getFileSize() K[ (NTp$E
{ 9cf:pXMi
int nFileLength = -1; @!`Xl*l
try{ }dp=?AFg
URL url = new URL(siteInfoBean.getSSiteURL()); .WPV dwV4U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =R#Qx,
httpConnection.setRequestProperty("User-Agent","NetFox"); pPcTrN'
|/09<F:L[
x$1]M DAGb
int responseCode=httpConnection.getResponseCode(); 0BIy>wy:
if(responseCode>=400) ;.TRWn#
{ /9HVY %n
processErrorCode(responseCode); k Mu8"Az
return -2; //-2 represent access is error Q^ pmQ
} B[V+ND'(
+)y^'Qs
{ jhr<
String sHeader; VY~yg*
k9L?+PD
U@-^C"R
for(int i=1;;i++) vH#huZA?7
{ g=;%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #=6E\&NC
//Utility.log(in.readLine()); W}5xmz
sHeader=httpConnection.getHeaderFieldKey(i); kL$!E9
if(sHeader!=null) A<1hOSCz\
{ n}'=yItVL1
if(sHeader.equals("Content-Length")) c17_2 @N
{ _tBTE%sO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S<4c r
break; sC='_h
} TMig-y*[
} %KmiH ;U
else u/M+u;
break; pL{U `5S
} BaSZ71>9]r
} H`0|tepz
catch(IOException e){e.printStackTrace ();} cFeXpj?GV
catch(Exception e){e.printStackTrace ();} yls ^cyX
d5oIH
'=Rs/EDME
Utility.log(nFileLength); Qk,I^1w?7
ch0{+g&
w)Q0_2p.
return nFileLength; Vl:^>jTki
} hnDBFQ{
[/Rf\T(,jn
cUA7#1\T=
//保存下载信息（文件指针位置） 89o/F+_b
private void write_nPos() Z@3i$8
{ ynE)Xdh
try{ kP-3"ACG
output = new DataOutputStream(new FileOutputStream(tmpFile)); <Dwar>}
output.writeInt(nStartPos.length); ;\=M;Zt
for(int i=0;i<nStartPos.length;i++) [N/"5 [
{ 4|CtRF<L
// output.writeLong(nPos); %`r?c<P}
output.writeLong(fileSplitterFetch.nStartPos); [/e<l&y
output.writeLong(fileSplitterFetch.nEndPos); MBqt&_?K
} JwAYG5W
output.close(); ;i<|9{;
} tE)suU5Y
catch(IOException e){e.printStackTrace ();} prTw'~(B
catch(Exception e){e.printStackTrace ();} P;Ga4Q.
} Zo g']=
X4 A<[&F/
q U]gj@R
//读取保存的下载信息（文件指针位置） -(f)6a+H
private void read_nPos() MP!d4
{ iZM+JqfU|D
try{ hFH*B~*:#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !*oi!ysU;O
int nCount = input.readInt(); QNpqdwu%h
nStartPos = new long[nCount]; S/4^ d &Gr
nEndPos = new long[nCount]; QWzB6H]
for(int i=0;i<nStartPos.length;i++) ~v6OsH%vx
{ @te!Jgu{
nStartPos = input.readLong(); >_|O1H./4
nEndPos = input.readLong(); EUN81F?
} $shoasSuI
input.close(); .6`9H 1
} &(xH$htv1
catch(IOException e){e.printStackTrace ();} (X?%^^e!
catch(Exception e){e.printStackTrace ();} 4}4Pyjh
} 0@H|n^Md#
&NH$nY.r
NiU2@zgl
private void processErrorCode(int nErrorCode) ]%?YZn<{
{ G>1eFBh }
System.err.println("Error Code : " + nErrorCode); 1T-8K r
} M#As0~y
wPwXM!
*=+td)S/1
//停止文件下载 `Ye\p6v!+
public void siteStop() <8d^^0
{ UrYZ`J
bStop = true; QlO0qbG[y
for(int i=0;i<nStartPos.length;i++) PYM(Xz$
fileSplitterFetch.splitterStop(); vK_?<>
a hR ^
%l,,_:7{
} B[Zjfc
} 4KH45|;3
//负责部分文件的抓取 ~%SH3$
**FileSplitterFetch.java E#ul IgD
*/ &?*V0luP)
package NetFox; %jJ>x3$F
9hOJvQ2U]
fO0XA"=
import java.io.*; +eFFSt
import java.net.*; 2@%$;.
<iH`rP#
^OstR`U3
public class FileSplitterFetch extends Thread { 2\7`/,U6
:k.NbN$i\
pO ml8SQf
String sURL; //File URL %2XHNW
long nStartPos; //File Snippet Start Position rld67'KcE
long nEndPos; //File Snippet End Position `<\1[HJ\
int nThreadID; //Thread's ID X&0 uI*r
boolean bDownOver = false; //Downing is over @>E2?CV
boolean bStop = false; //Stop identical 2ioQb`=
FileAccessI fileAccessI = null; //File Access interface \Dd-Xn_b
}T%}wdj
4*e0 hWp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1rkE yh??
{ B:!W$<
this.sURL = sURL; Z(Bp 0a
this.nStartPos = nStart; V{^!BBQ
this.nEndPos = nEnd; V??dYB(
nThreadID = id; u"d~!j1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 89wU-Aggq
} oE(7v7iY
uoXAQ6k
L7VG`h;
public void run() = Wu *+paQ
{ bZ|FnY}FB
while(nStartPos < nEndPos && !bStop) UmQ?rS8d
{ ,:Lb7bFv>
[L:o`j
K9OYri^TQ
try{ xv&Q+HD
URL url = new URL(sURL); .8P.)%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JvT"bZk(o
httpConnection.setRequestProperty("User-Agent","NetFox"); "87ghj_}
String sProperty = "bytes="+nStartPos+"-"; 2U; t(,dn'
httpConnection.setRequestProperty("RANGE",sProperty); m<0&~rg
Utility.log(sProperty); /C4^<k\
<K8\n^i~c
wyQzM6:,yX
InputStream input = httpConnection.getInputStream(); *{yK 8
//logResponseHead(httpConnection); {6~l$
2EfF=Fm>
#@"<:!?z
byte[] b = new byte[1024]; AKRTBjG"
int nRead; av$/Om:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h3Q21D'f
{ _h":>
nStartPos += fileAccessI.write(b,0,nRead); DBCK2PlJ
//if(nThreadID == 1) Sp^9&^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l"2OP6d
} IjR'Qou5
RW}"2
yRiP{$E
Utility.log("Thread " + nThreadID + " is over!"); 5<ux6,E1{
bDownOver = true; j'BMAn ?
//nPos = fileAccessI.write (b,0,nRead); ##EYH1P]
} hYM@?/(q
catch(Exception e){e.printStackTrace ();} d\ ~QBr?
} dVFf.
} ODC8D>ZYl
tX"Th'Qi
yZ7,QsEsN
//打印回应的头信息 HfvTxaK
public void logResponseHead(HttpURLConnection con) Ie4hhW
{ S}ECW,K
for(int i=1;;i++) ]f_6 '|5A
{ 9>g,
String header=con.getHeaderFieldKey(i); 'I /aboDB
if(header!=null) stk9Ah
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y;AL'vm9
Utility.log(header+" : "+con.getHeaderField(header)); H03jDM8Q
else D*YM[sN`
break; 8kIR y
} =n' 4?W@
} ^-[?#]
bLd#xXl
X0M1(BJgGo
public void splitterStop() SJ};TEA
{ C,pJ`:P
bStop = true; '^FGc
} lME)?LOI
/M*a,o
@;H,gEH^
} p$x{yz3
" $ew~;z
wlEo"BA
/* IW%|G
**FileAccess.java S.d^T](
*//文件访问(定位，写) \0H's{uek
package NetFox; j`*#v
import java.io.*; ,57`D'
!DI{:I_h(
`/MvQ/
public class FileAccessI implements Serializable{ =l0Jb#d
}QsZ:J.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2d {y M(=(
RandomAccessFile oSavedFile; {|yob4N
long nPos; fz3lV
~35U]s@v
yin'vgQ
public FileAccessI() throws IOException ?l$Nf@-
{ 7zv1wb
this("",0); ]+m/;&0
} jOyvDY9\
j$TwL;
]d]JXt?)i
public FileAccessI(String sName,long nPos) throws IOException UEzb^(8>
{ ,E$@=1)
oSavedFile = new RandomAccessFile(sName,"rw"); !QT'L,_
this.nPos = nPos; 2"d!(J6}K
oSavedFile.seek(nPos); u]ZqOJXxu
} KV*xApb9y
v (2GX
DS%\SrC
public synchronized int write(byte[] b,int nStart,int nLen) /De^
{ 2AVa(
int n = -1; ?^EXTU85`"
try{ f5GdZ_
oSavedFile.write(b,nStart,nLen); >Z;jY*
n = nLen; *\o/q[
} 1<h>B:
catch(IOException e) Vm|Y$C
{ {" 4e+y
e.printStackTrace (); p*8-W(u)
} \6 93kQ
q;:6_Qr
;kJu$U
return n; 3J=Y9 }
} dna6QV>A
Bs MuQ|!
NcAp_q? 4
} k3t78Qg
~WpGf,
n3`&zY
/* SgEBh
**SiteInfoBean.java tL+OCLF;
*/ :~ A%#
package NetFox; wO>L#"X^v
:SsUdIX;P
7E@+
public class SiteInfoBean { p<v.Q
i#%a-I:M
wfjc/u9W6R
private String sSiteURL; //Site's URL }BmS)Jq
private String sFilePath; //Saved File's Path U5]pi+r
private String sFileName; //Saved File's Name t nS+5F
private int nSplitter; //Count of Splited Downloading File _7D_72
4TwQO$C
2nFy`|aA%
public SiteInfoBean() Y= 7%+WyD
{//nSplitter的缺省值为5 P(>(K{v
//default value of nSplitter is 5 iHp\o=#
this("","","",5); Z.wA@ ~e
} M@thI%lR
9F^;!
b`_w])Y@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &VBd~4|p
{ f2,1<^{
sSiteURL= sURL; P=5NKg
sFilePath = sPath; V >,Z-&.%
sFileName = sName; o_Si mJFK
this.nSplitter = nSpiltter; ?K@t0a
I=Oy-
SxjCwX">
} ./p|?pu
do-c1;M
+} mk>e/
public String getSSiteURL() K+T.o6+
{ i%#$*
return sSiteURL; =_[Z W
} ntP|\E
-~4+w
SjdZyJa
public void setSSiteURL(String value) R1-k3;v^
{ J@9}`y=K
sSiteURL = value; ~^vC,]hU
} -K[782Q
p[2GkP
jvVi%k
public String getSFilePath() b8f+,2Tk
{ htPqT,L
return sFilePath; ^I]{7$6^
} L"<B;u5pM
a9~"3y
:h:@o h_=
public void setSFilePath(String value) (XH2Sy
{ IB|]fzy
sFilePath = value; 9B+wYJp
} +/?iCmW
s~},y]YV
E-1"+p
public String getSFileName() ^UA(HthY
{ ]Fb0Az
return sFileName; %TrF0{NR90
} $gMCR b,
%So]3;'
XV'fW~j\
public void setSFileName(String value) yW.COWL=)
{ L<(VG{)Z
sFileName = value; Zwe[_z!*D
} k*-NsNPw$
x:t<ZG&Xwg
Ewo*yY>
public int getNSplitter() (3*UPZv
{ &2EBk=X
return nSplitter; nEy]`
} tk/`%Q
*(cU]NUH_
YYRT.U'
public void setNSplitter(int nCount) $gp!w8h
{ ^t'3rft
nSplitter = nCount; &k T"oK
} F3ZxhkF
} J -Qh/d%]
i9UI,b%X
LNQSb4
/* wUi(3g|A
**Utility.java ?kt=z4h9(
*/ | W#~F&{]
package NetFox; OYf{?-QD
~_!ts{[E
Xz;b,C&*t
public class Utility { .F0]6#(
#B\=Aa`*
JatHSW7j9
public Utility() ^Y^"'"
{ c!&Qj
s0{ NsK>
!W1eUY
} Xy#VQ{!
JZ`L%
//线程睡眠 N_C_O$j
public static void sleep(int nSecond) xKp0r1}
{ |0{ i9.=
try{ Kla:e[{
Thread.sleep(nSecond); um8AdiK
} R9.HD?H@
catch(Exception e) U 5`y
{ @~jxG%y86
e.printStackTrace (); ~uPk
} )LswSV
} ~Sy-gaJ
I{dl%z73
//日志 i=QqB0
public static void log(String sMsg) +Z?[M1g
{ 6b:DJ
System.err.println(sMsg); ~HP LV
} eX<K5K.B
wsg//Ec]
FU@uH U5fd
public static void log(int sMsg) Wp*sPZ
{ R'EW7}&
System.err.println(sMsg); U($^E}I2(
} L? ;/cO^
} ,0T)Oc|HL/
o_yRn16
xQz#i-v
/* "2h5m4
**TestMethod.java A9BxwQU#
*/ @;9()ad
package NetFox; xbC~C~#
Zd>ZY,-5
!cCg/
public class TestMethod { ^`&HWp
|t\KsW
ci7~KewJ*
public TestMethod() _hoAW8i
{ ///xx/weblogic60b2_win.exe 0]a15
try{ u~71l)LA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'P/taEi=R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a!.!2a&t
SiteFileFetch fileFetch = new SiteFileFetch(bean); spiDm:Xe
fileFetch.start(); P$h;SK
} -fM1$/]
catch(Exception e){e.printStackTrace ();} }W "(cYN_
h}6b&m
y@9Y,ZR*
} H!JWc'(<$
EHWv3sR-
DN|vz}s
public static void main(String[] args) -IvL+}K
{ $i&\\QNn
new TestMethod(); eH=c|m]!P
} \|!gPc%s
} S 1ibw\'
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