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)); ml6u1+v5
} m&*JMA;^
for(int i=0;i<nEndPos.length-1;i++) d$t40+v
{ pTJX""C
nEndPos = nStartPos[i+1]; ",yc0 2<
} *bd[S0l
nEndPos[nEndPos.length-1] = nFileLength; X6\ sF"E
} oDn|2Sdqd
} Qkcjr]#^$
aC%&U4OS
.iG&Lw\,
//启动子线程 z//VlB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -0Cnp/Yj@
for(int i=0;i<nStartPos.length;i++) 5T@aCC@$h
{ Qm4o7x{q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [P~hjmJ(y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C0jj(ku&
nStartPos,nEndPos,i); @-HG`c ct
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _oG&OJ@
fileSplitterFetch.start(); v&a4^s
} x3 >
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =WIJ>#Go<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tM4Cx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Hnk:K9u.B:
nEndPos = " + nFileLength); CVNj-&vj
// fileSplitterFetch[nPos.length-1].start(); vi.w8>CE
;&V s4
ntFT>g{B
//等待子线程结束 Ep9W-n?}
//int count = 0; `h:34RC;
//是否结束while循环 >-8cU_m7s
boolean breakWhile = false; ",6M)3{|c
.*g0w`H5pU
JN+_|`
while(!bStop) 21hv%CF\9
{ Q7Iw[=;\
write_nPos(); 0:w"M<80
Utility.sleep(500); ,#MCn
breakWhile = true; #$1Z
'R-3fO???
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for(int i=0;i<nStartPos.length;i++) W-NDBP:
{ Gx`Lks
if(!fileSplitterFetch.bDownOver) wO?{?+I`q
{ (aOv#Vor]%
breakWhile = false; '5&s=M_
break; .7K7h^*F
} .X# `k
} Z}$TKO*u
if(breakWhile) [sB 9gY(
break; VD_$$Gn*q
|$?bc3
]a5 f2lE
//count++; lXcx@#~
//if(count>4) AGLscf.
// siteStop(); '!/<P"5t
} J8mdoVt
yKO`rtP
`BlI@6th
System.err.println("文件下载结束！"); !pD*p)`s
} BNL;Biyt7
catch(Exception e){e.printStackTrace ();} w!fE;H8w6
} ZYC<Wb)I
8F._9U-EN
IiG6<|d8H
//获得文件长度 #O+),,WS
public long getFileSize() EK4d_L]I
{ r-:Uz\gM
int nFileLength = -1; \[y`'OD~
try{ N;\'N ne
URL url = new URL(siteInfoBean.getSSiteURL()); hEp(A8g)bQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'FDef#P<
httpConnection.setRequestProperty("User-Agent","NetFox"); G K7![p
_H5o'>=
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int responseCode=httpConnection.getResponseCode(); cXKjrL[b
if(responseCode>=400) /Njd[=B
{ 3.*8)NW
processErrorCode(responseCode); p>4-s, W
return -2; //-2 represent access is error ; #&yn=^
} INJEsz
~{jcH
G|!on<l&
String sHeader; nCdR EXw
8|\8O@
g\&g N
for(int i=1;;i++) ]GW]dM
{ 5fd]v<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Jcrw#l8|C
//Utility.log(in.readLine()); L6|oyf
sHeader=httpConnection.getHeaderFieldKey(i); :gWu9Y|{
if(sHeader!=null) toBHkiuD
{ NgP&.39U
if(sHeader.equals("Content-Length")) ~v|>xqWV
{ %5"9</a&G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \D*KGd]M0
break; H _zo1AW
} 6\q]rfQ
} mc? Vq
else J;8IY=
break; lww!-(<ww
} 3 :<WY&9
} #."-#"0
catch(IOException e){e.printStackTrace ();} $Avjnm
catch(Exception e){e.printStackTrace ();} s;01u_
/rnu<Q#iH
{Tq_7,8
Utility.log(nFileLength); YUtC.TR1
C26>BU<
K;?m';z0
return nFileLength; pZqq]mHK
} [\v}Ul
Whm,F^
+0nJ
//保存下载信息（文件指针位置） 3TeY%5iVt
private void write_nPos() 4;yKOQD|
{ <lx+/o
try{ $_"'&zQ'
output = new DataOutputStream(new FileOutputStream(tmpFile)); )rn*iJ.e8
output.writeInt(nStartPos.length); 7&jTtKLj
for(int i=0;i<nStartPos.length;i++) cPyE 6\lN
{ a|t$l=|DD
// output.writeLong(nPos); sBvzAVBL
output.writeLong(fileSplitterFetch.nStartPos); `yrB->|vG
output.writeLong(fileSplitterFetch.nEndPos); I9_RlAd
} g+vva"
output.close(); gY/"cq
} SJb&m-
catch(IOException e){e.printStackTrace ();} PUp6Q;AdQ
catch(Exception e){e.printStackTrace ();} J\twZ>w~0
} n'n/Tu
%*A0#F
x<tb
//读取保存的下载信息（文件指针位置） IA8f*]?
private void read_nPos() Gp?a(-K5
{ ?+@n3]`0
try{ _S<3\%(0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kCWV r
int nCount = input.readInt(); ]b2pG'
nStartPos = new long[nCount]; +h|`/ &,
nEndPos = new long[nCount]; \)#kquH/l
for(int i=0;i<nStartPos.length;i++) nv*FT
{ ry`Ho8N
nStartPos = input.readLong(); s4X>.ToMC
nEndPos = input.readLong(); 5d Eh7XL
} ]sf7{lVT
input.close(); eenH0Ovv
} KKja/p
catch(IOException e){e.printStackTrace ();} (y=C_wvqZ
catch(Exception e){e.printStackTrace ();} =upeRY@u5
} '}ptj@,
h5*JkRm
^me-[ 5
private void processErrorCode(int nErrorCode) ugdQAg
{ ;#g"(
System.err.println("Error Code : " + nErrorCode); + [iQLM?zo
} B3pCy~*5
~ (|5/ p7t
.F4>p=r
//停止文件下载 [A+ >^ {
public void siteStop() [L3=x;U
{ xK *b1CB
bStop = true; 9&-dTayIz
for(int i=0;i<nStartPos.length;i++) sXLq*b?
fileSplitterFetch.splitterStop(); |HiE@
BRw .]&/
}MJy +Z8&
} 5kc/Y/4o
} }^ApJS(FQ
//负责部分文件的抓取 ],@rS9K
**FileSplitterFetch.java ($q-_m
*/ 0.`/X66;V
package NetFox; i?p$H0bn
m|SUV
Z^bQ^zk-
import java.io.*; &jS>UsGh
import java.net.*; m~iXl,r
pj\u9 L_
v> LIvi|]
public class FileSplitterFetch extends Thread { G?L HmTHg
pR*VdC _mY
O*hDbM2QQw
String sURL; //File URL ak7bJ~)X=
long nStartPos; //File Snippet Start Position lEH65;Nh*
long nEndPos; //File Snippet End Position rMdt:`
int nThreadID; //Thread's ID $njUXSQ;
boolean bDownOver = false; //Downing is over z6KCv(zvB
boolean bStop = false; //Stop identical QmQ=q7
FileAccessI fileAccessI = null; //File Access interface ^=GC3% J
5dx$HE&b)
E(*0jAvO[z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QE^$=\l0
{ 2~Kgv|09
this.sURL = sURL; cVXLKO
this.nStartPos = nStart; {j{u6i
this.nEndPos = nEnd; 8v:T.o;<
nThreadID = id; `LrHKb aP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L^r#o-H<
} +Zb;Vn4
LD+{o4i
!44/sr'
public void run() j b!x:
{ |tKsgj
while(nStartPos < nEndPos && !bStop) 57'*w]4f
{ {0L1X6eg
[@&m4 7
i[O& )N,c
try{ g?c xp+
URL url = new URL(sURL); aHV;N#Lx3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vHgi<@u
httpConnection.setRequestProperty("User-Agent","NetFox"); ;0Q4<F
String sProperty = "bytes="+nStartPos+"-"; 1XrO~W\=
httpConnection.setRequestProperty("RANGE",sProperty); `"Jj1O@
Utility.log(sProperty); JYMiLph<
J!AgBF N4
TtJH7
InputStream input = httpConnection.getInputStream(); TYy?KG>:'
//logResponseHead(httpConnection); +vw\y
j5(Z_dm'
|hKDvH
byte[] b = new byte[1024]; "SNn^p59k
int nRead; [meO[otb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r7RIRg_
{ 8^kGS-+^
nStartPos += fileAccessI.write(b,0,nRead); /,BD#|
//if(nThreadID == 1) L 8c0lx}Nn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mu\6z_e
} kVuUjP6(c
%2}-2}[>
](Xb_xMf
Utility.log("Thread " + nThreadID + " is over!"); >,v`EIg
bDownOver = true; pf]xqhL
//nPos = fileAccessI.write (b,0,nRead); 272q1~&
} [xK3F+
catch(Exception e){e.printStackTrace ();} ,bZL C
} aEBu *`-j
} C+*d8_L
Yc`o5Q\>
GiJ *Wp
//打印回应的头信息 nB_?ckj,
public void logResponseHead(HttpURLConnection con) b}2ED9HG\
{ J9..P&c\
for(int i=1;;i++) loEPr5bL
{ ~jWn4 \
String header=con.getHeaderFieldKey(i); H/"-Z;0{
if(header!=null) uY{|szC^2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !-g{[19\
Utility.log(header+" : "+con.getHeaderField(header)); ##q2mm:a9P
else L s G\OG
break; ww)<E`eGi
} 'Y?"{HZ
} ~b(i&DVK
3(``#7
QpF;:YX^3
public void splitterStop() #F:p-nOq
{ S\^Pha q
bStop = true; i9rN9Mq?O
} ]q\b,)4 e
?#Ge.D~u
?)/#+[xa
} LY+@o<>
m\;R2"H%
[m->5H
/* LmRy1T,act
**FileAccess.java [RS|gem`
*//文件访问(定位，写) T!uM+6|Y
package NetFox; !d'GE`w T
import java.io.*; R1PkTZP&
;[(oaK@+n
pD(j'[
public class FileAccessI implements Serializable{ p$O.> [
} j<)L,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {GvJZ!,RCg
RandomAccessFile oSavedFile; N>Xo_-QCY
long nPos; rr/B=O7
G`+T+
Ig$(3p
public FileAccessI() throws IOException |U~<3.:m:
{ .GbX]?dN
this("",0); }pDqe;a{
} 02Y]`CXj
8<5]\X
ih)zG
public FileAccessI(String sName,long nPos) throws IOException ysJQb~2q
{ #akpXdXs
oSavedFile = new RandomAccessFile(sName,"rw"); zofa-7'Bn
this.nPos = nPos; w2Us!<x
oSavedFile.seek(nPos); EJj.1/]|r
} 16w|O|^<
m&xW6!x
GC<l#3+
public synchronized int write(byte[] b,int nStart,int nLen) &\#sI9
{ dW_KU}
int n = -1; \@Ts+7%
try{ @#<D ^"
oSavedFile.write(b,nStart,nLen); Amp#GR1CA
n = nLen; ]99|KQ<s
} 9"NF/)_
catch(IOException e) :Hn6b$Vy8
{ u&^b~#T
e.printStackTrace (); }bs+-K
} ?OId\'q
6RG)`bu
VX].3=T8
return n; Nc1"g1JR
} -]L6=
LVX[uWEM
W~6EEyD%
} WeJl4wF
O80<Z#%j`
<x@}01~
/* " f <Z=c
**SiteInfoBean.java [V^WGW2oY
*/ ?*2CpM&l
package NetFox; 4<9=5q]
pSoiH<33
VAWF3
public class SiteInfoBean { 5BWH-2HsB
1Y/s%L
-jW.TT h]
private String sSiteURL; //Site's URL hwu]Er.gn
private String sFilePath; //Saved File's Path RdWRWxTn8+
private String sFileName; //Saved File's Name <_h~w}
private int nSplitter; //Count of Splited Downloading File O#b6mKPt;t
N+++4;
'GB.UKlR
public SiteInfoBean() 7_%"BVb"
{//nSplitter的缺省值为5 0x'#_G65y
//default value of nSplitter is 5 FO=4:
this("","","",5); ]*vdSr-J
} t'VV>;-RO=
T3~k>"W
Q(@U2a8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z?}dq-Vh&
{ XJ;D=~
sSiteURL= sURL; E'G4Y-
sFilePath = sPath; 4y)P>c
sFileName = sName; ;LcVr13J/
this.nSplitter = nSpiltter; A$<.a'&T!
y6LWx:
!LggIk1
} lU@]@_<
o1Ph~|s*8
4~y(`\0?4
public String getSSiteURL() `)` n(B
{ h^?\xm|
return sSiteURL; yGWxpzmRS
} ^X0P'l&D2
3 N.~mR
~$ng^D
public void setSSiteURL(String value) I`p+Qt
{ e91aK
sSiteURL = value; m=?KZ?U`
} &f"-d
L0*nm.1X
"7!;KHc
public String getSFilePath() plUZ"Tr
{ -}=i 04^
return sFilePath; t\NqR
} t0o`-d(
Z9MdD>uwi
X*M#FT-
public void setSFilePath(String value) q;QbUO
{ !u_Y7i3^
sFilePath = value; ;gBRCZ
} i;NUAmx
f47Od-\-
qDv93
public String getSFileName() IOb*GTb
{ bu |a0h7e
return sFileName; >=RmGS
} z8QAo\_I(
?3%`bY+3;
?3*l{[@J
public void setSFileName(String value) {p;zuCF1
{ lp<g\
sFileName = value; JQ,1D`?.a
} 4kG,*3&2
qR(\5}
LA@w:Fg
public int getNSplitter() wT `a3Ymm
{ 3D`YZ#M
return nSplitter; TR<<+
} Q?3Gk%T0[
Yj)#k)x
@n(Z$)8tR
public void setNSplitter(int nCount) ?mWw@6G,
{ y9_K, g
nSplitter = nCount; ?%`@ub$
} CPP` qt%f
} o>/YAX:.!T
aemc2b*
c%&:6QniZ
/* {P{bOe
**Utility.java HR ;)|j{!
*/ ROk5]b.
package NetFox; _h X]%
/h*>P:i].
5D_fXfx_|
public class Utility { T-5nB>)
%7"X(Ts7B
}"=AG
public Utility() TYJ:!
{ 0BH_'ZW
bty/
eU<]o< \Qo
} HRiL.DS
EGZb7:Y?
//线程睡眠 :cq9f2)
public static void sleep(int nSecond) (xVsDAp=@
{ 9T|IvQK8
try{ 6`v7c!7
Thread.sleep(nSecond); y($%;l
} po$ /7
catch(Exception e) dl~%MWAVb
{ EmODBTu+
e.printStackTrace (); G8r``{C!
} q{t*34R
} ~ECD`N<YF
=0G!f$7^i
//日志 9G+V;0Q
public static void log(String sMsg) B x (uRj
{ KuMF^0V%c
System.err.println(sMsg); `FsH}UPu b
} ]3g?hM6
L{(QpgHZ
.h9l7 nZt
public static void log(int sMsg) Sh?4ri@:
{ o>7ts&rk
System.err.println(sMsg); i{ \%e
} JaK}|
} qUxRM_7U
co9 .wB@
9nH?l{As
/* Nkp)Ax&
**TestMethod.java e_/b2"{
*/ xo&]RYG[<
package NetFox; '1$!jmY
[o.B
oiX+l5`pz
public class TestMethod { ppFe-wY
xia|+
t`+'r}=d
public TestMethod() * 1Od-3
{ ///xx/weblogic60b2_win.exe ~i21%$
try{ 8HRmQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L5qwWvbT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qQ0cJIISb\
SiteFileFetch fileFetch = new SiteFileFetch(bean); bks/`rIA
fileFetch.start(); }J7zTj~{
} HW7; {QMg
catch(Exception e){e.printStackTrace ();} glDh([
({NAMc*
Fr%d}g
} :"l-KQ0
"h|'}7p
Qu7T[<
public static void main(String[] args) 'w14sr%
{ me'd6!O9-
new TestMethod(); v*9<c{a
} (XXheC
} h68]=KyK
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