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( qO fek
} (}:n#|,{M
for(int i=0;i<nEndPos.length-1;i++) o 2Okc><z
{ Y#[>j4<T
nEndPos = nStartPos[i+1]; bo%v(
} oY$L
nEndPos[nEndPos.length-1] = nFileLength; "2FI3M=
} QTKN6P
} \'AS@L"Wj^
sKU?"|G81G
,*}5xpX
//启动子线程 7Rix=*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x-3!sf@
for(int i=0;i<nStartPos.length;i++) IX]K"hT
{ hr)CxsPoRQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sH}q&=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :lGH31GG
nStartPos,nEndPos,i); 2-#:Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Z6tRf;B
fileSplitterFetch.start(); Pu-/*Fx
} Er]lObfQo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {?zbrgQ<Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7=gv4arRwt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rt5eN:'qY
nEndPos = " + nFileLength); wWU5]v
// fileSplitterFetch[nPos.length-1].start(); o"5[~$O
oF9c>^s
#Lq{_Y
//等待子线程结束 ^%<t^sE
//int count = 0; !"e~HZmr
//是否结束while循环 OYC\+ =
boolean breakWhile = false; 4EB&Zmg[K
1G6MO
:Ky *AI
while(!bStop) eJm7}\/6`
{ buv*qPO
write_nPos(); ^twJNm{99
Utility.sleep(500); Q'mLwD3>
breakWhile = true; y_Tc$g~
S5$sB{\R
D#?jddr-
for(int i=0;i<nStartPos.length;i++) ju= +!nGUa
{ >.]'N:5
if(!fileSplitterFetch.bDownOver) QV@NA@;XZ
{ B,Gt6cUq
breakWhile = false; *~0Ko{Avc
break; ]XAJ|[]sj*
} %}*0l8y
} p>c`GDU
if(breakWhile) 8!c#XMHV
break; W6>SYa
.;'3Roi
;C+g)BW
//count++; nHB=*Mj DV
//if(count>4) qK9\oB%s7
// siteStop(); ~^GY(J'
} ?(!<m'jEy
5r$X
xa?#wY b
System.err.println("文件下载结束！"); .PhH|jrCW^
} q:9#Vcw
catch(Exception e){e.printStackTrace ();} ^ld?v
} VZJ[h{ 6
^S'#)H-8C3
Rt{`v<
//获得文件长度 W?B(Jsv
public long getFileSize() BIr24N
{ K[XFJ9
int nFileLength = -1; )E2^G)J$W
try{ i{$h]D_fD
URL url = new URL(siteInfoBean.getSSiteURL()); ,z1fiq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DG&[.dR+
httpConnection.setRequestProperty("User-Agent","NetFox"); JvZNr?_w%
bxS+ R\
D3>;X=1
int responseCode=httpConnection.getResponseCode(); j+_pF<$f:
if(responseCode>=400) 4&+;n[D
{ B:pIzCP
processErrorCode(responseCode); (xJZeY)-b^
return -2; //-2 represent access is error L,XWX8
} jb~/>I^1
mu1Lgs$;
8>}^W
String sHeader; s]X]jfA.
0uf'6<fR
*vss
for(int i=1;;i++) mu(EmAoenQ
{ V0Z\e _I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u{o!j7
//Utility.log(in.readLine()); / xfg4
sHeader=httpConnection.getHeaderFieldKey(i); Pkm3&sW
if(sHeader!=null) H9^DlIv('
{ U1>VKP;5Nn
if(sHeader.equals("Content-Length")) {cNH|
{ '~1uJ0H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q6?}/p
break; 'e3[m
} _TRO2p0
} {iv!A=jld
else r#K;@wu2
break; '5ZtB<
} D&xbtJd
} `+!GoXI
catch(IOException e){e.printStackTrace ();} M=}vDw]Q
catch(Exception e){e.printStackTrace ();} S'I{'jP5
+N9(o+UrU
f8Xe%"<
Utility.log(nFileLength); s57-<&@J9
@CSTp6{y
%mhnd):
return nFileLength; GYD`
} NY5?T0/[
#l(cBM9sz
?5%|YsJP_
//保存下载信息（文件指针位置） {&'u1yR
private void write_nPos() %#.HFK
{ 4DL;/Z:
try{ .Jt&6N
output = new DataOutputStream(new FileOutputStream(tmpFile)); =Of!1TR(
output.writeInt(nStartPos.length); WheJ 7~
for(int i=0;i<nStartPos.length;i++) b ;Vy=f
{ *CA7 {2CX
// output.writeLong(nPos); Ba$Ibq,r/
output.writeLong(fileSplitterFetch.nStartPos); i6^COr
output.writeLong(fileSplitterFetch.nEndPos); w/KCuW<
} {5f?y\Z
output.close(); (]|rxmycA
} 2/9P&c-rp
catch(IOException e){e.printStackTrace ();} |/?)u$U<
catch(Exception e){e.printStackTrace ();} rKDMIECrm
} >qJRpO
!cs+tm3
uLw$`ihw
//读取保存的下载信息（文件指针位置） n=vW oU9
private void read_nPos() o,!r t1&0
{ b@OL!?JP
try{ y7I')}SC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |]5g+sd
int nCount = input.readInt(); V}#2pP
nStartPos = new long[nCount]; H4HWr6
nEndPos = new long[nCount]; fz`+j -u
for(int i=0;i<nStartPos.length;i++) x,\PV>
{ a*}ZT,V
nStartPos = input.readLong(); GdqT4a\S
nEndPos = input.readLong(); oEHUb?(p
} -ISI!EU$
input.close(); bF88F_
} silTL_$
catch(IOException e){e.printStackTrace ();} xGQ958@
catch(Exception e){e.printStackTrace ();} eCYgi7?
} ^X%{]b K
9w -t9X>X
`}s$cgEG
private void processErrorCode(int nErrorCode) t@Qs&DZ7k
{ H)$-T1Wx4
System.err.println("Error Code : " + nErrorCode); Rx$5#K!%M
} Ix,`lFbH
N#')Qz:P
8J:6uO c|
//停止文件下载 %Dg]n4f
public void siteStop() "WTnC0<
{ */Oq$3QGsV
bStop = true; Efsfuv
for(int i=0;i<nStartPos.length;i++) w0x%7mg@
fileSplitterFetch.splitterStop(); {89F*
R{~Yh.)~
/@5X0m
} #c5 NFU}9
} C3af>L@}
//负责部分文件的抓取 =GpO}t">
**FileSplitterFetch.java 3S-nsMs.
*/ .c'EXuI7),
package NetFox; JJ3(0 +
(m[]A&u
uj$b/I>.'
import java.io.*; Be{7Rj v
import java.net.*; OLc/Vij;
)o'&f"/
8CxC`*L(
public class FileSplitterFetch extends Thread { C7`FM@z
1(`>9t02/?
U:eahK
String sURL; //File URL dA[Z\
long nStartPos; //File Snippet Start Position !GcH )
long nEndPos; //File Snippet End Position j_E$C.XU{g
int nThreadID; //Thread's ID T<\Q4Coth
boolean bDownOver = false; //Downing is over 2G8f4vsC[
boolean bStop = false; //Stop identical !Y3w]_x[:
FileAccessI fileAccessI = null; //File Access interface J7BfH,o
Ij hC@5qk
DCv~^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m!s/L,iJJ
{ $-m`LF@
this.sURL = sURL; 6elmLDMni\
this.nStartPos = nStart; p]uwGWDI
this.nEndPos = nEnd; ir<HC 'D[
nThreadID = id; ]<mXf~zg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BlQu9{=n
} tWYKW3~]
v;X'4/M
87zsV/
public void run() <">tB"="b
{ ZYoWz(
while(nStartPos < nEndPos && !bStop) q&0Jl
{ /#M|)V*wn
*P&ZE
\D] N*
try{ _NAKVzo-
URL url = new URL(sURL); ]R/VE"-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6X5`npf
httpConnection.setRequestProperty("User-Agent","NetFox"); Hd6g0
String sProperty = "bytes="+nStartPos+"-"; 5QU7!jbI
httpConnection.setRequestProperty("RANGE",sProperty); 2E^zQ>;01
Utility.log(sProperty); a!}.l< )
wn[q?|1
k/W$)b:Of`
InputStream input = httpConnection.getInputStream(); zFh JLH*C
//logResponseHead(httpConnection); lL~T@+J~
dI<s)!
Mt)`hR+2
byte[] b = new byte[1024]; m98j`t
int nRead; c6cGl]FL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MV5'&" ,oB
{ s{#ZRmc2B
nStartPos += fileAccessI.write(b,0,nRead); ++-\^'&1
//if(nThreadID == 1) 0n+Wv@/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U@dztX@u
} CF3Z`xD
}wrZP}zM>
Q*mzfsgr
Utility.log("Thread " + nThreadID + " is over!"); ;JMd(\+-
bDownOver = true; j"*ZS'0
//nPos = fileAccessI.write (b,0,nRead); mXT{)pU
} $Ml/=\EHOg
catch(Exception e){e.printStackTrace ();} PA;RUe
} r'M|mQ$s>
} FMB\$(g
oop''6`C%
NvWwj%6]
//打印回应的头信息 306C_M\$
public void logResponseHead(HttpURLConnection con) CXGq>cQ=d
{ u1O?`
for(int i=1;;i++) E~]8>U?V
{ ^HumyDD6
String header=con.getHeaderFieldKey(i); ^EE3E'
if(header!=null) Y[9x\6 _E
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7Xm7{`jH
Utility.log(header+" : "+con.getHeaderField(header)); .asHFT7]9
else a0OH
break; Asicf{HaX
} :BG/]7>|V
} .?9+1.`
?c0OrvM
a02;Zl
public void splitterStop() ?as)vYP
{ v:(_-8:F
bStop = true; @*'|8%
} HJ]\VP9Zb
JX(JZ/8B^
O`U&0lKi'
} Oz!#);v
,T?8??bZ
"40Jxqt
/* \[oU7r}?/V
**FileAccess.java &bBK#d*-u?
*//文件访问(定位，写) 7yxZe4~|#
package NetFox; \k_0wt2x1
import java.io.*; 5FcKY_
:Eq=wbAw
1tU}}l
public class FileAccessI implements Serializable{ BL6t>
8;/`uB:zV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )h&s.k
RandomAccessFile oSavedFile; bvzeUn
long nPos; h"cLZM:6
o&)O&bNJ
{;]:}nA
public FileAccessI() throws IOException Q[`J=
{ /~V.qisZ
this("",0); DesvnV'{`
} %m1k^
c%c/mata?
(-DA%
public FileAccessI(String sName,long nPos) throws IOException ?#ue:O1
{ +lmMBjDa
oSavedFile = new RandomAccessFile(sName,"rw"); u}hQF$a"
this.nPos = nPos; }2-<}m9}
oSavedFile.seek(nPos); O= PFr"
} #+p30?r0y
Lzu;"#pw
I^sWf3'db
public synchronized int write(byte[] b,int nStart,int nLen) YG$2ySkDhE
{ "&%: 9O
int n = -1; 5*~Mv<#
try{ $8h^R#
oSavedFile.write(b,nStart,nLen); |^Nz/PN
n = nLen; W@v@|D@
} 4thLK8/c5g
catch(IOException e) q3Re F_
{ p*)RP2
e.printStackTrace (); !/, 6+2Ru
} N r5 aU6]
eYBo*
[RG&1~
return n; [,)yc/{*
} De,4r(5
@=q,,t$r
e|u|b
} 5f2ah4 g
t_5b
cy8+@77
/* ysD@yM,
**SiteInfoBean.java }q9;..oL
*/ "ut:\%39.
package NetFox; 68?oV)fE
4a]m=]Hm
4&;.>{:;
public class SiteInfoBean { B8-v!4b0`
GCCmUR9d
N8|=K_;&
private String sSiteURL; //Site's URL hM\<1D CKG
private String sFilePath; //Saved File's Path CLU!/J$!
private String sFileName; //Saved File's Name 'jWd7w~(
private int nSplitter; //Count of Splited Downloading File c0jdZ#H
[b-27\b
n~N>c*p
public SiteInfoBean() e_s9E{(
{//nSplitter的缺省值为5 *f|9A/*B3
//default value of nSplitter is 5 T">-%-t
this("","","",5); fI(u-z~,
} +N1oOcPC>C
?F'gh4
=ZM#_uW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8$a4[s
{ {Buoo~
sSiteURL= sURL; &\8.y2=9p
sFilePath = sPath; o8\@R
sFileName = sName; _l,?Y;OF
this.nSplitter = nSpiltter; c\~H_ ~F
Q>f^*FyOw<
!PUbaF-.6
} ^p(t*%LM
e\i K
)iadu
public String getSSiteURL() .E:[\H"
{ bHE'R!*
return sSiteURL; z52T"uW
} K_j$iHqLF
<cG .V|B
"GoNTM5h
public void setSSiteURL(String value) qCK)FOU
{ [C d"@!yA
sSiteURL = value; ^ a%U *>P
} M"[s5=:Lo
B%!z7AT
2zR*`9$
public String getSFilePath() yZ3/Ia>,
{ /=Bz[O
return sFilePath; lQQXV5NV
} iJ_`ZM.w
cAJKFuX"
'8`{u[:
public void setSFilePath(String value) I$0JAy
{ 7 y}b (q=
sFilePath = value; k+S+: 5
} -a(f-
=1t#$JG
_l]`Og@Y
public String getSFileName() <K!5N&vh
{ F4X/ )$Dk
return sFileName; )BNm~sP
} Q(h,P+
F^bC!;~x
wm0vqY+N$
public void setSFileName(String value) WL-+;h@VQ
{ Im%|9g;P
sFileName = value; Zzr+p.
} n m(yFX?=
f"Yj'`6
j{N;2#.u
public int getNSplitter() +:1ay^YI
{ ~a m]G0
return nSplitter; =Run
} t$=FcKUV}f
U~Aw=h5SD
6"Q/Y[y
public void setNSplitter(int nCount) , RfU1R
{ &3v{~Xg)
nSplitter = nCount; L^rtypkJ
} {LTb-CB
} Qfo'w%px
H4 Y7p
pWH8ex+
/* j~c7nWfX
**Utility.java d$)'?Sf]h
*/ (WiA
package NetFox; !OM9aITv[
\lHi=}0
=" K;3a`GI
public class Utility { 5P{dey!
K !8+~[
T:x5 ,vpM
public Utility() >1:s.[&
{ @8C^[fDL
At%g^
AoyU1MR(
} pcNVtp'V
kbBD+*
//线程睡眠 VpMpZ9oM<
public static void sleep(int nSecond) xtf]U:c
{ uxk&5RY
try{ =]oBBokV
Thread.sleep(nSecond); >JS\H6
} {y<[1Pms
catch(Exception e) L5%~H?K(
{ >`= '~y8
e.printStackTrace (); M]!\X6<_
} w<j6ln+nM
} ;+K:^*oJ
g.f!Uc{
//日志 @;_r`AT7
public static void log(String sMsg) DU$]e1
{ &w:"e'FG`
System.err.println(sMsg); 0:Js{$ZL4
} kM]:~b2
,0[8/)$M
xr!FDfM.K
public static void log(int sMsg) is{I5IR\/
{ 1JgnuBX"
System.err.println(sMsg); mB;W9[
} <oV _EZ
} i:OD)l
lT$Vv=M
tr7FV1p
/* z_!P0`
**TestMethod.java hd9fD[5
*/ AM##:4
package NetFox; yXY8 oE
TJ7on.;
lE08UEk1i
public class TestMethod { }txHuq1Q.
K"eR6_k
gj\r>~S
public TestMethod() ;3Fgy8T
{ ///xx/weblogic60b2_win.exe 2i', e
try{ #^<7VS!x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O(,Ezyx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m\U@L+L
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?nrd$,
fileFetch.start(); ^C>i(j&
} Lcplc"C
catch(Exception e){e.printStackTrace ();} 9C[3w[G~C
Zp@p9][C
QpS0iUG
} 3s\2 9gq
hnL"f[p@gC
s!Y>\3rMW
public static void main(String[] args) e{OmW
{ 82Nh;5Tr
new TestMethod(); QV+('
} )gvXeJ
} rj$u_y3S*
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