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)); Jz}`-fU`
} ;L,i">_%u[
for(int i=0;i<nEndPos.length-1;i++) %s497'
{ q{&\nCy
nEndPos = nStartPos[i+1]; O\CnKNk,
} ta6>St7.
nEndPos[nEndPos.length-1] = nFileLength; lb$_$+@Vr
} RIQ-mpg~(k
} 5 w(nttYH
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iO&*WIbg
//启动子线程 l$1NI#&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IU<lF)PF$
for(int i=0;i<nStartPos.length;i++) ; PncJe5x
{ ?JG^GD7D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _1Q6FI5iR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cnS;9=,&
nStartPos,nEndPos,i); IITUM)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pz34a@%"
fileSplitterFetch.start(); |_+#&x
} d)S`.Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aZ$5"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BPa,P_6(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?m5EXe
nEndPos = " + nFileLength); ~+j2a3rv-{
// fileSplitterFetch[nPos.length-1].start(); 9Vqy<7i1
ywl=@
tu Y+n2
//等待子线程结束 4d%0a%Z
//int count = 0; PxgJ7d
//是否结束while循环 ]/kpEx
boolean breakWhile = false; A+!,{G
S :8
z~X/.>
while(!bStop) 8 eK8-R$
{ O>pv/Ns
write_nPos(); t[J=8rhER
Utility.sleep(500); Vi:^bv
breakWhile = true; (w#t V*
/W)A[jR
Y*$>d/E
for(int i=0;i<nStartPos.length;i++) CxeW5qc
{ qxb]UV,R
if(!fileSplitterFetch.bDownOver) 4")`}T
{ (bQ3:%nD
breakWhile = false; GkX Se)#p
break; t+}wTis
} GE(~d'
} >9rZVNMU
if(breakWhile) B Z|A&;
break; BH1h2OEe#
5gtf`ebs/
jtlRom}
//count++; \$ipnQv
//if(count>4) $GFR7YC 7
// siteStop(); sde>LZet/
} v8*)^-Fx
IO)#O<
.a]#AFX
System.err.println("文件下载结束！"); .Zczya
} >PSO]%mE
catch(Exception e){e.printStackTrace ();} :${tts2g
} ?:J_+?{E
8s$6R|ti
GeTk/tU
//获得文件长度 ##=$$1Ki
public long getFileSize() uy'seJ
{ [&n[p?
int nFileLength = -1; QM F
try{ qK a}O*
URL url = new URL(siteInfoBean.getSSiteURL()); Q2VF+g,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b&+zAt.
httpConnection.setRequestProperty("User-Agent","NetFox"); );h(D!D,
cdt9hH`Cd
FKTF?4+\U
int responseCode=httpConnection.getResponseCode(); Bz/Vzc(
if(responseCode>=400) z}ar$}T
{ f\<r1
processErrorCode(responseCode); i]%f94
return -2; //-2 represent access is error ;Zd_2CZ
} #y83tNev
=EP`,zqn$9
8|i'~BFHs
String sHeader; TU0-L35P1
Cf=H~&`Z
Io]FDPN
for(int i=1;;i++) Q v9q~l
{ 3F2IL)Hn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sllT1%?
//Utility.log(in.readLine()); b&U1^{(
sHeader=httpConnection.getHeaderFieldKey(i); Af;Pl|Zh[
if(sHeader!=null) MjMDD
{ _]`7et\=
if(sHeader.equals("Content-Length")) OOqT0wN
{ Sf*)Z3f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OoSk^U)
break; b_31\
} <?nIO
} :5NMgR.d
else v|%41xOsr
break; U>E: Ub0r
} 7AV{ h[J
} =X4Fn^w"4O
catch(IOException e){e.printStackTrace ();} 9(N
catch(Exception e){e.printStackTrace ();} fjRVYOG#
?G,4N<]Nu
VL9wRu;
Utility.log(nFileLength); +`HMl;0m
:jiuu@<
$D^\[^S
return nFileLength; G?W:O{n3
} 0|P=S|%~
KZppQ0
+F;2FD$
//保存下载信息（文件指针位置） =}`d
private void write_nPos() UBaXS_c\
{ GcVQz[E
try{ * 65/gG8>
output = new DataOutputStream(new FileOutputStream(tmpFile)); g3tE.!a5-
output.writeInt(nStartPos.length); / FcRp,"
for(int i=0;i<nStartPos.length;i++) URsx>yx
{ _?c.m*)A
// output.writeLong(nPos); nGF +a[Z
output.writeLong(fileSplitterFetch.nStartPos); k~>(XG[x&
output.writeLong(fileSplitterFetch.nEndPos); %B%_[<B
} -zg*p&F
output.close(); Rt8[P6e"q
} "V|Rq]_+%
catch(IOException e){e.printStackTrace ();} C`.YOkpj
catch(Exception e){e.printStackTrace ();} NL9.J@"b
} 7>yd
l]]NVBA])
cgb>Naa<
//读取保存的下载信息（文件指针位置） @;/Pl>$|'G
private void read_nPos() 51k}LH
{ ._}}@V_/
try{ b'z $S+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fd)8lK[KJ"
int nCount = input.readInt(); /@9Q:'P
nStartPos = new long[nCount]; ,?GwA@~$k:
nEndPos = new long[nCount]; ;(NTzBq!1
for(int i=0;i<nStartPos.length;i++) !l'nX
{ 2/?Zp=|j\
nStartPos = input.readLong(); iXWHI3
nEndPos = input.readLong(); vpu#!(N
} K"!rj.Da
input.close(); "hyfo,r
} mA(kq
catch(IOException e){e.printStackTrace ();} i2qN 0?n
catch(Exception e){e.printStackTrace ();} ?{J1&;j*
} !:+U-mb*
TK5$-6k
xg p)G!
private void processErrorCode(int nErrorCode) $JFjR@j
{ ZX_QnSNZ?
System.err.println("Error Code : " + nErrorCode); g#I`P&
} DI0& _,
) 57'<
8{4'G$6
//停止文件下载 2"6L\8hd2
public void siteStop() c^|8qvS$
{ r]e{~v/
bStop = true; 1]}\h]*
for(int i=0;i<nStartPos.length;i++) *"^X)Y{c+l
fileSplitterFetch.splitterStop(); ?qQ{]_q1&.
Zr}>>aIJ]k
UC&$8^
} JQ+Mg&&Q
} \%r#>8c8
//负责部分文件的抓取 NZGO8u
**FileSplitterFetch.java kHK<~srB
*/ ,88B@a
package NetFox; ,.Gp_BI
L`t786 (M
ZRhk2DA#FF
import java.io.*; XU'(^Y8Imz
import java.net.*; 4f j}d.?
UB@(r86d
uz8eS'8
public class FileSplitterFetch extends Thread { "|6(.S+o
rbf5~sw&8+
X}[1Y3~y
String sURL; //File URL n[/D>Pi
long nStartPos; //File Snippet Start Position W@}@5,}f>
long nEndPos; //File Snippet End Position 1XS~b-St
int nThreadID; //Thread's ID jHq+/\
boolean bDownOver = false; //Downing is over q`AsnAzo&
boolean bStop = false; //Stop identical 3\2&?VAjR
FileAccessI fileAccessI = null; //File Access interface 5]{rim
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!UzE&CirV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,5 8-h?B0v
{ 3B#fnj
this.sURL = sURL; ,$]m1|t@z
this.nStartPos = nStart; wgSFL6Ei
this.nEndPos = nEnd; 7gtaI3
nThreadID = id; ~U<j_j)z4.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (fc_V[(m"
} ,>6mc=p
o5],c9R9b
a[t"J*0
public void run() i% 0qN
{ V^(W)\
while(nStartPos < nEndPos && !bStop) |QrVGm@2
{ `~axOp9N
HmXxM:[4;
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try{ yJx,4be
URL url = new URL(sURL); JA >&$h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9'X"a
httpConnection.setRequestProperty("User-Agent","NetFox"); B4OFhtYE
String sProperty = "bytes="+nStartPos+"-"; KjA7x
httpConnection.setRequestProperty("RANGE",sProperty); 0>Kgz!I
Utility.log(sProperty); }2=~7&)
P EzT|uY
]_>38f7h
InputStream input = httpConnection.getInputStream(); |}l/6WHB
//logResponseHead(httpConnection); y]Q/(O
\hJLa
USE!
byte[] b = new byte[1024]; Ow0~sFz
int nRead; .ErR-p=-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~LH).\V
{ tjZS:@3 Z
nStartPos += fileAccessI.write(b,0,nRead); } BP.t$_
//if(nThreadID == 1) 7CT446
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7vqE@;:dt
} +5ql`C
%)}_OXWf:
ylmVmHmc
Utility.log("Thread " + nThreadID + " is over!"); LNgFk%EH
bDownOver = true; R<T5lkJ\/
//nPos = fileAccessI.write (b,0,nRead); Lz-(1~o
} <.|]%7
catch(Exception e){e.printStackTrace ();} ]{-ib:f~
} 5t-(MY
} `?N|{kb
f+Bv8 g
}g.)%Bw!
//打印回应的头信息 O sIvW'$\
public void logResponseHead(HttpURLConnection con) =rNI&K_<
{ #1>c)_H
for(int i=1;;i++) cTJG1'm
{ 6K.0dhl>`B
String header=con.getHeaderFieldKey(i); U_0"1+jbq
if(header!=null) XQ k,xQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9&4z4@on
Utility.log(header+" : "+con.getHeaderField(header)); cj3P]2B#
else %?`$#*f\%
break; &ZPyZj
} }!vJ+
} 4H%Ai(F}_
ue6&)7:~
sU?%"q
public void splitterStop() = :\o/)+
{ a/ Z\h{*
bStop = true; XgZ.UT
} DmpD`^?-L
`oH6'+fT`;
}W"/h)q
} g"v-hTx
*p%=u>?&
20RISj
/* Oc?]L&ap
**FileAccess.java $~.'Tnk)
*//文件访问(定位，写) )1!*N)$
package NetFox; I.}E#f/A'
import java.io.*; ~@Eu4ip)F
ER$qL"H U
Xkb\fR6<K
public class FileAccessI implements Serializable{ _QOZ`st
;l=ZW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .q(1
RandomAccessFile oSavedFile; =ET|h}I
long nPos; 3At%TA:
b$1W>
.qk_m-o
public FileAccessI() throws IOException ;JQ;LbEn
{ V17SJSC-
this("",0); Vq<\ixRi
} Qc]Ki3ls
x\R 8W8M
W~FM^xR?p
public FileAccessI(String sName,long nPos) throws IOException <C,lHt
{ "_ i:
oSavedFile = new RandomAccessFile(sName,"rw"); [oh0 )wzB
this.nPos = nPos; RwptFO
oSavedFile.seek(nPos); aoVfvz2Y
} -9z!fCu3
xF8^#J6>
GY,HEe]2r
public synchronized int write(byte[] b,int nStart,int nLen) v46 5Z
{ j>-O'CO
int n = -1; aaODj>
try{ y)e8pPDG
oSavedFile.write(b,nStart,nLen); ;HbAk`\1A
n = nLen; `suEN@^
} 48Z0aA~+
catch(IOException e) XIJW$CY
{ ruQ1Cph
e.printStackTrace (); zo~5(O@
} >Kjl>bq
&@h(6
gkw/Rd1oG
return n; sV`!4 u7%}
} _gl7Ma
&3_.k
K{WLo5HP
} 84}Pu%
Q'qz(G0
Qaeg3f3F3
/* qPG>0 O
**SiteInfoBean.java EAPjQA-B?
*/ Qt`;+N(
package NetFox; $zUHka
;S.o`z1GI
-L&%,%
public class SiteInfoBean { U8gf_R'
ev"f@y9Do
o!-kwtw`l
private String sSiteURL; //Site's URL 9O2??N7f
private String sFilePath; //Saved File's Path GI _.[
private String sFileName; //Saved File's Name y8arFG
private int nSplitter; //Count of Splited Downloading File Z]\VOA>
3JJEj1O
[;RO=
public SiteInfoBean() O; #qG/b1
{//nSplitter的缺省值为5 )~[rb<:)b
//default value of nSplitter is 5 x^]J^L45
this("","","",5); ?hh#@61
} BDiN*.w5
%;MM+xVVX
_my!YS5n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RR9G$}WS(
{ cy @",z
sSiteURL= sURL; gHmy?+)
sFilePath = sPath; *P0sl( &
sFileName = sName; Sxzt|{
this.nSplitter = nSpiltter; /k O <o&
cfhiZ~."T
' |Ia-RbX
} DICS6VG}
/JbO$A
;&i4QAo-
public String getSSiteURL() 'S#D+oF(1~
{ M>g%wg7Ah
return sSiteURL; w)7s]Ld
} m4~>n(
Xn=
w gU2q|
public void setSSiteURL(String value) &Fy})/F3v
{ >#[,OU}N
sSiteURL = value; Mp,aQ0bNS
} -?vII~a9y
9AP."RV
S\<nCkE^
public String getSFilePath() :TkR]bhm
{ fb|%)A=
return sFilePath; .{,fb
} n=qu?xu
!Y^3%B%
aaRc?b'/
public void setSFilePath(String value) N.F//n
{ `/RcE.5n\@
sFilePath = value; w 21g&
} @5tGI U;1
wrm ReT?
(,^jgv|I
public String getSFileName() D*}_L
{ qW 2'?B3<
return sFileName; GD@|XwK){
} Z# o;H$
hOj(*7__
&ieb6@RO`Q
public void setSFileName(String value) N:~CN1
{ y134m
sFileName = value; OOZxs?pR
} 8>AST,
X[J?
iCIU'yI
public int getNSplitter() 5ggsOqH
{ $A^OP{
return nSplitter; HyC826~-rI
} A;Av0@w
wu~?P`
S1U>Q~ZPA
public void setNSplitter(int nCount) 6H^=\
{ p(fL' J
nSplitter = nCount; WPDi)UX
} +j(7.6ia
} g27)$0&0
Wxa</n8S[n
71G\b|5
/* '#NDR:J"
**Utility.java ,;)_$%bHc
*/ 4,.[B7irR
package NetFox; ~nRbb;M
"5@\"L
1~y\MD*-j
public class Utility { L XHDX
% 8P8h%%Z
{y`n_
public Utility() [!Zyp`:
{ o?/fObV@(
y`a]##1j$M
_g%,/y 9y
} S7(tGD
z<OfSS_]R
//线程睡眠 *:"p*qV*
public static void sleep(int nSecond) K;*B$2Z#k
{ 5 51p* B2
try{ .f9&.H#
Thread.sleep(nSecond); 8fA8@O}
} F4$9r^21r
catch(Exception e) @*=eqO
{ k-I U}|Xz
e.printStackTrace (); '}9 %12\^h
} ]iry'eljy
} r<!/!}fE,
/)<Xoa
//日志 Sz-TarTF
public static void log(String sMsg) Le2rc*T
{ U*\1d
System.err.println(sMsg); F7\nG}#s
} FW:V<{f
h@@q:I=
DHVfb(H5e
public static void log(int sMsg) #&snl
{ Lklb
System.err.println(sMsg); nZ4@g@e2
} ]F srk
} R'$1,ie
$|VD+[jSV
p4@0Dz`Q
/* m%U$37A1
**TestMethod.java 8gW$\
*/ ZJV;&[$[
package NetFox; &W%fsy<
<x1,4a~
l}W"> yQ0
public class TestMethod { z'}z4^35,
Qn \=P*j
w_*$wVl
public TestMethod() m6o o-muAr
{ ///xx/weblogic60b2_win.exe eKe[]/}e9
try{ S7B?[SPrN[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /J!~0~F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gM&4Ur
SiteFileFetch fileFetch = new SiteFileFetch(bean); oT- Y
fileFetch.start(); G&@_,y|
} ?tkd5kE
catch(Exception e){e.printStackTrace ();} 8xx2+
4R&pb1eF
&?^"m\K4J*
} CJt(c,!z
RpzW-
5 ~YaXh^
public static void main(String[] args) `FByME
{ =z#j9'n$@
new TestMethod(); `t2Y IwOK
} qjH/E6GGg
} ese?;1r
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