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)); T=Q{K|JE
} ,IATJs$E
for(int i=0;i<nEndPos.length-1;i++) hd%F7D5
{ T5+b{qA
nEndPos = nStartPos[i+1]; 5R G5uH/-<
} ^TK)_wx
nEndPos[nEndPos.length-1] = nFileLength; ]>T/Gl1
} (2)9TpE;
} ee` =B
<L#r6y~H
{0{$.L
//启动子线程 :?W:'% (`[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `sC8ro@Fm
for(int i=0;i<nStartPos.length;i++) g<3>7&^
{ 9DKB+K.1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $>m<+nai'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D8XXm lo
nStartPos,nEndPos,i); 7s3<}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GdY^}TJrh
fileSplitterFetch.start(); "S#hzrEdYI
} zH4#\d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &>t1A5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A*;h}\n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :\RB ^3;
nEndPos = " + nFileLength); `q*ABsj
// fileSplitterFetch[nPos.length-1].start(); Z] }@#/ n
0q!{&pt
o 4wKu
//等待子线程结束 j pV
//int count = 0; syvi/6
//是否结束while循环 H>9$L~
boolean breakWhile = false; =Ybu_>
aQ\O ]gCE
\C|06Bs$
while(!bStop) zf#&3K'k
{ r6G)R+#
write_nPos(); ~=*_I4,+r
Utility.sleep(500); 4ebGAg?_
breakWhile = true; xy>mM"DOH
*%sYajmD
sBL^NDqa2
for(int i=0;i<nStartPos.length;i++) 8^T$6A[b
{ {eV_+@dT
if(!fileSplitterFetch.bDownOver) RL9P:] ^
{ U"Oq85vY
breakWhile = false; :wm^04<i
break; EZV$1pa
} &Y$rVBgQ
} H\vO0 <X
if(breakWhile) 5H2|:GzUc
break; 1cega1s3xR
HR
ysPW<
//count++; 24fWj?A|^
//if(count>4) 1<5yG7SZ
// siteStop(); f^ qQ5N
} RJM(+5xQ|
Fjb[Ev
eKOTxv{
System.err.println("文件下载结束！"); mH"`46
} Q<qIlNE
catch(Exception e){e.printStackTrace ();} _i#Z'4?2E
} `R^VK-=C
eF@E|kK
\=~Ap#Mpc4
//获得文件长度 duCm+4,.
public long getFileSize() DGnswN%n1
{ rOGJ%|%(
int nFileLength = -1; Xs/hqIXB
try{ I(4k{=\ph]
URL url = new URL(siteInfoBean.getSSiteURL()); j?A+qk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XijQ)}'C3
httpConnection.setRequestProperty("User-Agent","NetFox"); Mtr~d
XA68H!I
YX(%jcj*
int responseCode=httpConnection.getResponseCode(); ~S9nLb:O{
if(responseCode>=400) C Qebb:y
{ FKP^f\!M
processErrorCode(responseCode); j&9~OXYv
return -2; //-2 represent access is error NINiX(
} *?S\0a'W@
gFH_^~7i8p
N>_7Ltw/
String sHeader; |j<'[gB\p
]F~5l?4u#
#*~Uu.T
for(int i=1;;i++) t +_G%tv
{ 6~s,j({^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iu .{L(m
//Utility.log(in.readLine()); NKRXY~zHh
sHeader=httpConnection.getHeaderFieldKey(i); 7~&Y"&
if(sHeader!=null) ~Y(M>u.+!
{ @?U5t1O<
if(sHeader.equals("Content-Length")) +-"#GL~cC
{ v|xlI4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )Jc>l;G(M
break; C+Z"0\{o
} LuVj9+1 S
} a5iMCmL+
else SV~xNzo~
break; 1Sy#*
} ,rKN/{M!
} lc#H%Qlg
catch(IOException e){e.printStackTrace ();} DuWP)#kg
catch(Exception e){e.printStackTrace ();} ~gf$ L9
LLE~V~j
,#A,+!4
Utility.log(nFileLength); ) E\pQ5&
tv0xfAV
g 0L 4
return nFileLength; UpITx]y?"m
} km^AX:r1
z(ajR*\#
B@4#y9`5
//保存下载信息（文件指针位置） I'gnw~
private void write_nPos() "~ /3
{ \yqiv"'
try{ ;Cwn1N9S
output = new DataOutputStream(new FileOutputStream(tmpFile)); gOkO8P6P8
output.writeInt(nStartPos.length); 1;h>^NOq
for(int i=0;i<nStartPos.length;i++) l@Ki`if
{ YW5E |z
// output.writeLong(nPos); gSC@uf
output.writeLong(fileSplitterFetch.nStartPos); Pzqgg43Xf
output.writeLong(fileSplitterFetch.nEndPos); Z`W.(gua
} 1ysA~2
output.close(); buoz La
} .q=X58tHu
catch(IOException e){e.printStackTrace ();} b7n~z1$
catch(Exception e){e.printStackTrace ();} `XnFc*L 1
} }8svd#S+
ns3k{l#
oTL "]3`'
//读取保存的下载信息（文件指针位置） ,uw&)A
private void read_nPos() y|aWUX/a
{ yDKX,
try{ L=$P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0MOAd!N
int nCount = input.readInt(); L \$zr,=C
nStartPos = new long[nCount]; |!|`Je3 K
nEndPos = new long[nCount]; \8pbPo=x
for(int i=0;i<nStartPos.length;i++) g/E;OcFaO
{ >eXNw}_j
nStartPos = input.readLong(); 23>?3-q
nEndPos = input.readLong(); B[$e;h*Aw[
} g (~&
input.close(); ldxUq,p
} ck}y-,>,[O
catch(IOException e){e.printStackTrace ();} &qr7yyY
catch(Exception e){e.printStackTrace ();} oH;Y}h
} F,D&
V$@2:@8mo
vD(;VeW[
private void processErrorCode(int nErrorCode) VS`S@+p
{ dU\fC{1Z
System.err.println("Error Code : " + nErrorCode); T|m+ULp~
} =:b/z1-v
#: F)A_Y
3lJK[V{'#'
//停止文件下载 aV ^2
public void siteStop() `8Om*{xg
{ ~$cw]R58,9
bStop = true; j}|6k6t
for(int i=0;i<nStartPos.length;i++) <D=%55
fileSplitterFetch.splitterStop(); z/TRqD
[7B&<zY/?
\KEL.}B9E
} ;HC"hEc!
} 83dOSS2
//负责部分文件的抓取 Pk,^q8;
**FileSplitterFetch.java 6e*JCf>
*/ Y,a.9AWw)
package NetFox; @.5Ybgn
_V;J7Vz
wjl?@K
import java.io.*; Kb}N!<Z*
import java.net.*; u0x\5!?2
i"b*U5k
Y8d%L;b[D
public class FileSplitterFetch extends Thread { < ;g0?M\
{ sZrI5
kN_LD-
String sURL; //File URL 6(z.(eT
long nStartPos; //File Snippet Start Position JvG t=v
long nEndPos; //File Snippet End Position b/ynCf8X
int nThreadID; //Thread's ID bi5'-.B
boolean bDownOver = false; //Downing is over u&<LW4
boolean bStop = false; //Stop identical iZ58;`
FileAccessI fileAccessI = null; //File Access interface 0+L5k!1D
C>;}CH|X
iU3co|q7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V +hV&|=
{ J@$>d
this.sURL = sURL; uIR_p\)
this.nStartPos = nStart; F[+sc Mx!G
this.nEndPos = nEnd; )TWf/Lcp
nThreadID = id; LvR=uD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 55AG>j&41
} w#o<qrpHf
0 cQf_o
:9)>!+|'
public void run() 6"wY;E
{ 0}ZuF.
while(nStartPos < nEndPos && !bStop) )JjfPb64
{ z`BRz&
Fb_~{q
XnNK)dUT}
try{ P}PSS#nn
URL url = new URL(sURL); > {:8c-\2}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YRwS{e*u
httpConnection.setRequestProperty("User-Agent","NetFox"); :c6%;2
String sProperty = "bytes="+nStartPos+"-"; A*$vk2VWw
httpConnection.setRequestProperty("RANGE",sProperty); wM|-u/9+
Utility.log(sProperty); UVUHLu|^
-wO`o<
#><.zZ
InputStream input = httpConnection.getInputStream(); 5?Bi+fg
//logResponseHead(httpConnection); fpzTv3D=I
L'c4i[~s
Um|:AT}`^
byte[] b = new byte[1024]; { u;ntDr
int nRead; 3(CUC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V9MA)If>
{ <uAqb Wu
nStartPos += fileAccessI.write(b,0,nRead); f5O*Njl
//if(nThreadID == 1) 0!^{V:DtQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 20J:_+=]
} `aC#s3[
4iKT
co;2s-X
Utility.log("Thread " + nThreadID + " is over!"); kt@+UK."
bDownOver = true; h rZ\ O?j
//nPos = fileAccessI.write (b,0,nRead); :]]amziP&
} $k!t&G
catch(Exception e){e.printStackTrace ();} Zw }7vD0
} 6h5*b8LxA
} *zmbo >{(
2;q6~Y,
]2( %^#qBG
//打印回应的头信息 l\S..B +
public void logResponseHead(HttpURLConnection con) c~>M7e(
{ ^x4gUT-Wy
for(int i=1;;i++) SmRU!C$A
{ L5>>gG,
String header=con.getHeaderFieldKey(i); 2\7]EW
if(header!=null) Gjzhgz--
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j\W+wnAgk
Utility.log(header+" : "+con.getHeaderField(header)); L-MpdC
else o`&idn|,
break; j6Vuj/+}
} "=qdBG9
} Q@M,:0+cy
Q.5a"(d@
ov|s5yH8e
public void splitterStop() VJwzYl
{ `]fY9ZDKs
bStop = true; :@pmgp
} Hiw{1E:rW
OnD+/I
;ymUMQ%;/
} h'N,oDB)
]o_ Ps|
haY.rH]z
/* D L$P
**FileAccess.java ."MBKyg6
*//文件访问(定位，写) ]qrO"X=
package NetFox; u|Db%)[
import java.io.*; >0f5Mjug
n0EKNMO
&<L+;k~P%
public class FileAccessI implements Serializable{ ~ Iv[
u[cbRn,W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b|4h2iuM
RandomAccessFile oSavedFile; Qs~;?BH&
long nPos; d,$[633It}
'a4xi0**I
@O4m-Oosi
public FileAccessI() throws IOException /Cwt4.5
{ >bmL;)mc&
this("",0); 398%16}
} R|Ykez!D
T8ZsuKio]
K+n6.BzW
public FileAccessI(String sName,long nPos) throws IOException f\Pd#$3
{ Rh:\/31~
oSavedFile = new RandomAccessFile(sName,"rw"); 03#r F@e
this.nPos = nPos; cA_v*`YL
oSavedFile.seek(nPos); Yj;$hV8j(
} cz.-cuD[iD
@1rF9< 4g
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public synchronized int write(byte[] b,int nStart,int nLen) PF4Cs3m/
{ }"_S;[{d
int n = -1; %vMi kibI
try{ YsLEbue
oSavedFile.write(b,nStart,nLen); #K ]k
n = nLen; /EWF0XV!
} #OG_OI
catch(IOException e) M)Y`u
{ Ib]{rmaP
e.printStackTrace (); 84|Hn|4t
} D @T,j4o
#Mi>f4T;
\Q]2Zq
return n; tTC[^Dji
} TVYO`9:CW
?. CA9!|
@|r*yi
} Rh,*tS
L{osh0
sexnO^s
/* Av7bp[OD
**SiteInfoBean.java e>Is$+[`7
*/ R$NH [Tz
package NetFox; WCU[]A
Wrt3p-N"D
HlLF<k~}
public class SiteInfoBean { w0VJt<e*
Gv3a<Knn4
~[l2"@
private String sSiteURL; //Site's URL G^oBu^bq~
private String sFilePath; //Saved File's Path Xv6z>z.
private String sFileName; //Saved File's Name = R; 0Ed&b
private int nSplitter; //Count of Splited Downloading File 8!E$0^)c|
X+Xjf(
pX|\J>u)
public SiteInfoBean() 6i,d|
{//nSplitter的缺省值为5 0l{').!_
//default value of nSplitter is 5 7w YSP&$
this("","","",5); j2g#t
} }hEBX:-
Cd]d[{NJ;
"wA3l%d[Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,Rz,[KI|
{ 61b,+'-
sSiteURL= sURL; *p p1U>,
sFilePath = sPath; cKdy)T%;
sFileName = sName; J3g>#N]='(
this.nSplitter = nSpiltter; >\[sNCkf
w=y!|F
hP,SvN#!2
} [Kx_%Le
0}-&v+
zZGPA j
public String getSSiteURL() @\b*a]CV
{ !uy?]l
return sSiteURL; M"ZP s
} AZxOq !B
{PWz:\oaD
pNCk~OM
public void setSSiteURL(String value) !JJCG
{ ey@y?X=
sSiteURL = value; 2j*\n|"}{
} tihb38gE
i%D/@$\D6
vUY?Eb[
public String getSFilePath() A<QYW,:|
{ )k- 7mwkZ
return sFilePath; VNx}ADXu]
} `{<2{}2M
mRxL%!
+);o{wfW
public void setSFilePath(String value) YNH>^cD1
{ 3@\vU~=P:
sFilePath = value; [AfV+$
} (/Hq8o-Fw
\bZbz/+D
M +~guTh
public String getSFileName() o#4Wn'E
{ VEd\*
return sFileName; i=#r JK=
} u,*$n'l]
\/. Of]YQ
Lb{~a_c
public void setSFileName(String value) m{I_E G
{ 6^s]2mMfk
sFileName = value; Z#3wMK~
} fZ 17
e}-uU7O
)|q,RAn
public int getNSplitter() RHz'Dz>0
{ VsNqYFHes&
return nSplitter; ?so3Kj6H
} T<mk98CdE
'[{M"S
4ehajK
public void setNSplitter(int nCount) &:nWZ!D
{ mAX]m1s
nSplitter = nCount; )U`H7\*)
} kS[k*bN0
} ^-f5;B`\i
x\3tSP7Vp
|Gzd|$%Oq
/* |bVNlL"xN
**Utility.java Xa Yx avq
*/ >OBuHqC
package NetFox; U3&*,xeU@H
I^qk`5w
/1gKc}rB2
public class Utility { o.Mb~8Yu
ec)G~?FH
I,l%6oPa
public Utility() \4bma<~a
{ 0 jVuFl
0/#XUX 4
"mSDL:$
} O_FT@bo\
.KIAeCvl\
//线程睡眠 #Z"N\49
public static void sleep(int nSecond) @R9
{ 0v,DQJ?w8
try{ 44 o5I:
Thread.sleep(nSecond); ^>72<1U%
} m32OE`s
catch(Exception e) L>).o%(R
{ i/,G=yA
e.printStackTrace (); $xvEYK
} EJNj.c-#
} ~bWqoJ;Q
;KbnaUAS8
//日志 w(k7nGU]
public static void log(String sMsg) X6N^<Z$
{ lmz{,O
System.err.println(sMsg); /thCu%%9A
} uY5f mM9
aL-V9y
D@"q2 !
public static void log(int sMsg) a`~$6 "v
{ hOO)0IrIM*
System.err.println(sMsg); Z5bmqhDo[
} @J!)o d
} KVSy^-."
@:oMlIw;
49 fs$wr@
/* <Lyz7R6
**TestMethod.java |*Z'WUv
*/ |/]bpG'z
package NetFox; +`mJh\*
3S_KycE{
Yu9Ccj`
public class TestMethod { g5M-Vu
|2 g }i\
Ipb4{A&"\
public TestMethod() U:J~Oy_Z
{ ///xx/weblogic60b2_win.exe hh|'Uq3
try{ `Rm2G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [A yq%MA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P=KOw;bs
SiteFileFetch fileFetch = new SiteFileFetch(bean); L_<&oq
fileFetch.start(); dGQy=T:
} cJ&l86/l1
catch(Exception e){e.printStackTrace ();} 4Qz
[j1SX-NX
7`~h'(k
} KG4~t=J`
;k (}~_
t1n'Ecm(
public static void main(String[] args) $B2* x$
{ GNZQj8
new TestMethod(); *xkbKkm
} $QNfy.6Tn
} .^,fw=T|1
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