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)); UqHk2h-
} R]L$Ld< ij
for(int i=0;i<nEndPos.length-1;i++) aTXmF1_n
{ 5,Rxc=
nEndPos = nStartPos[i+1]; ~^Ceru"<
} E<6Fjy
nEndPos[nEndPos.length-1] = nFileLength; oY)xXx
} ob=](
} 02+ k,xFb
EyU5r$G
Wgp}v93
//启动子线程 `p qj~s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Jkf%k3H3I*
for(int i=0;i<nStartPos.length;i++) xLX2F
{ \_GG6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v/ $~ifY"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {nQ?+o3
nStartPos,nEndPos,i); (^),G-]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w~+C.4=7
fileSplitterFetch.start(); barY13)$U
} tNk.|}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K14FY2"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |j2b=0Rpk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d`eX_]Z
nEndPos = " + nFileLength); `LroH>_
// fileSplitterFetch[nPos.length-1].start(); :`jB1rI
st4WjX_Q
Hsdcv~Xr;l
//等待子线程结束 Vv|%;5(
//int count = 0; Dt#( fuk#
//是否结束while循环 !!KA9mP
boolean breakWhile = false; V= wWY*C
e^ Aw%t
:r+BL@9
while(!bStop) }Mv$Up
{ s:O8dL /
write_nPos(); 0gevn
Utility.sleep(500); |!Uul0O
breakWhile = true; 6y0CEly>3#
fpPB_P{Ua
dQ.:xu}~
for(int i=0;i<nStartPos.length;i++) s!g06F
{ `T#Jiq E
if(!fileSplitterFetch.bDownOver) Hoj'zY
{ )(/Bw&$
breakWhile = false; Kb$6a'u7
break; G~ONHXL
} /l%+l@
} E[=#Rw!*
if(breakWhile) +|K/*VVn`
break; evQk,;pIm
|a|##/
~[Fh+t(Y
//count++; y$,j'B:;4m
//if(count>4) ABIQi[A
// siteStop(); AqZ()p*z
} F'^y?UP[
n/ CP2A
"KHe6otmi_
System.err.println("文件下载结束！"); p=T6Ix'_2e
} LLV1W0VO=P
catch(Exception e){e.printStackTrace ();} 8ioxb`U
} o4qB0h
D:56>%y@
^ZD0rp(l
//获得文件长度 xXQW|#X\
public long getFileSize() V9\y*6#Y,
{ DQy;W ov
int nFileLength = -1; CkeqK
try{ ]vQU(@+I
URL url = new URL(siteInfoBean.getSSiteURL()); +\GuZ5`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6DxT(VU}
httpConnection.setRequestProperty("User-Agent","NetFox"); ":vF[6K6
@wTRoMHPQ
%7SGQE#W_~
int responseCode=httpConnection.getResponseCode(); PBY;SG~
if(responseCode>=400) =vD}O@tN
{ p9Y`_g`
processErrorCode(responseCode); a IgV"3
return -2; //-2 represent access is error R-]i BL
} {SJnPr3R
dz"HO!9
Aw,#oG {N
String sHeader; &m~
Uv|^k8(
Y{c+/n3d
for(int i=1;;i++) MngfXm
{ PESJ7/^E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w@$_2t
//Utility.log(in.readLine()); I`KBj6n
sHeader=httpConnection.getHeaderFieldKey(i); [h@MA|
if(sHeader!=null) G1S:hw%rp
{ rT!9{uK
if(sHeader.equals("Content-Length")) n1@ Or=5
{ q@%9Y3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Mb\[` 4z
break; Jo9!:2?
} c 6$n:
} eSA%:Is.
else 9 ?(P?H
break; &k0c|q]
} E?^A+)<"
} 2@+MT z
catch(IOException e){e.printStackTrace ();} b1t7/q
catch(Exception e){e.printStackTrace ();} s[tFaB1
]qNPOnlp
* ~4m!U_s
Utility.log(nFileLength); Nk/Ms:57y
^J7g)j3
R:FyCT_,
return nFileLength; *N?y<U
} u9^R ?y
dD}!E
jHWJpm(
//保存下载信息（文件指针位置） WA79(B
private void write_nPos() `Ef&h V
{ gKay3}w
try{ &m>txzo
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ea2&7
output.writeInt(nStartPos.length); ^jMo?Zwy
for(int i=0;i<nStartPos.length;i++) wfc[B;K\
{ S&m5]h!D
// output.writeLong(nPos); l5d> YTK+5
output.writeLong(fileSplitterFetch.nStartPos); L7&|
output.writeLong(fileSplitterFetch.nEndPos); w=H4#a?fc
} )QiHe}
output.close(); _ Oe|ZQ
} ofA6EmQ37
catch(IOException e){e.printStackTrace ();} vaEAjg*To<
catch(Exception e){e.printStackTrace ();} e{x|d?)8
} S.Fip_
B(%bBhs
QU{\ClW/?
//读取保存的下载信息（文件指针位置） P!)k4n
private void read_nPos() ~IE5j,SC
{ .DkDMg1US
try{ 5bzYTK&-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TAt9+\'
int nCount = input.readInt(); +6* .lRA
nStartPos = new long[nCount]; "@[xo7T
nEndPos = new long[nCount]; .iL_3:6f
for(int i=0;i<nStartPos.length;i++) XU#nqvS`.
{ 7#R& OQ
nStartPos = input.readLong(); Z0e+CEzq
nEndPos = input.readLong(); S hM}w/4
} jdYv*/^
input.close(); ptmPO4f
} =w.#j-jR
catch(IOException e){e.printStackTrace ();} 4l?98
catch(Exception e){e.printStackTrace ();} (A*r&Ak[
} s `r tr
'c<@SVF{Zz
m~Dq0 T
private void processErrorCode(int nErrorCode) 7=ZB;(`L1
{ e-os0F
System.err.println("Error Code : " + nErrorCode); ~j\/3;^s
} G\H@lFh
xy|-{
Tj{!Fx^H
//停止文件下载 ZtEHP`Iin
public void siteStop() V_(?mC
{ gHlahg
bStop = true; S@7A)
for(int i=0;i<nStartPos.length;i++) =fHt|}.K
fileSplitterFetch.splitterStop(); *qG=p`
"7)F";_(^
1{"fmV
} _V{WXsOx(
} @/JGC%!
//负责部分文件的抓取 ?XGZp?6
**FileSplitterFetch.java !@/?pXt|
*/ va;d[D,
package NetFox; EW4XFP4 c
(U`7[F
9~,eu
import java.io.*; nL+*Ja
import java.net.*; |<ke>j/6n
u3,b,p
fV}\
public class FileSplitterFetch extends Thread { z<<` 1wqg
q{7s.m >
66'TdF]"
String sURL; //File URL @-b}iP<T
long nStartPos; //File Snippet Start Position MO#%w
long nEndPos; //File Snippet End Position 4g1u9Sc0
int nThreadID; //Thread's ID CaBTqo
boolean bDownOver = false; //Downing is over <tF]>(|M
boolean bStop = false; //Stop identical C [2tH2*#
FileAccessI fileAccessI = null; //File Access interface Y\p yl
?o.G@-
(rwbF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %q*U[vv
{ ]K9x<@!
this.sURL = sURL; KH KqE6
this.nStartPos = nStart; Z=F=@<!
this.nEndPos = nEnd; N%B#f\N
nThreadID = id; WejY b;KS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +&?VA!}.
} C#-x 3d-{
z|b4w7I
i2j)%Gc}
public void run() 9i`LOl:;
{ `z=MI66Nl
while(nStartPos < nEndPos && !bStop) VS).!;>z
{ ,OasT!Sr
WJ.PPq>]F
f8&=D4)-w
try{ Pdn.c1[-a
URL url = new URL(sURL); 4_"ZSVq]#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I'@ }Yjm|
httpConnection.setRequestProperty("User-Agent","NetFox"); '[-/Xa['
String sProperty = "bytes="+nStartPos+"-"; S&=B&23T
httpConnection.setRequestProperty("RANGE",sProperty); 2d>PN^x
Utility.log(sProperty); _&z>Id`w
cn\_;TYiJ
z H \*v'
InputStream input = httpConnection.getInputStream(); rzTyHK[
//logResponseHead(httpConnection); %d7iQZb>
p5H Mg\hT
c"z%AzUV'
byte[] b = new byte[1024]; X! ]~]%K$y
int nRead; v[|iuOU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xxiLi46/
{ \D[BRE+
nStartPos += fileAccessI.write(b,0,nRead); HIU@m<
//if(nThreadID == 1) sS|zz,y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;4_n:XUgo;
} <^~F~]wnH
aH$~':[93
^$L/Mv+
Utility.log("Thread " + nThreadID + " is over!"); g&bO8vR=
bDownOver = true; UiSc*_N"
//nPos = fileAccessI.write (b,0,nRead); *=Fcu@
} CeJ|z{F\
catch(Exception e){e.printStackTrace ();} 0I_;?i
} fU}w81oe
} @3@%9E
#SXXYh-e
f65Sr"qB3
//打印回应的头信息 Qh[t##I/
public void logResponseHead(HttpURLConnection con) O>Sbb2q?"
{ Xm4wuX"e=
for(int i=1;;i++) Vg+SXq6G
{ d;^?6V
String header=con.getHeaderFieldKey(i); !eq]V9
if(header!=null) b?$09,{0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G](K2=
Utility.log(header+" : "+con.getHeaderField(header)); ,*4"d._Y
else 'SieZIm)
break; L$xRn/\
} 6)$_2G%Zq
} 5Z[D(z
}B-A*TI<h
ah92<'ix
public void splitterStop() o7+/v70D
{ M<)2
bStop = true; P Cf|^X#B
} 0o]K6b
q{hq.KZ
,2`d3u^CW
} hLvv:C@
=/;_7|ssd
a)1,/:7'
/* <@A^C$g
**FileAccess.java 3EvA 5K.
*//文件访问(定位，写) 1I`D$Xq~:
package NetFox; T_uuFL
import java.io.*; %&XX*& q
IT(c'}
a{+oN $
public class FileAccessI implements Serializable{ [}2.CM
>I?Mi{'a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yLx.*I^6
RandomAccessFile oSavedFile; &EPEpN R
long nPos; 1,T9HpM
:RsPGj6
C=IH#E=
public FileAccessI() throws IOException w8 $Qh%J'<
{ )^N8L<
this("",0); E/ZJ\@gzD
} aA`q!s.%A
}|Tg_+
7]%il[
public FileAccessI(String sName,long nPos) throws IOException `tG_O
{ Y:,R7EO{!
oSavedFile = new RandomAccessFile(sName,"rw"); j>xVy]v=|
this.nPos = nPos; a*j <TR
oSavedFile.seek(nPos); !&O/7ywe
} p*,P%tX
C|\^uR0
wW8 6rB
public synchronized int write(byte[] b,int nStart,int nLen) Db=>7@h3C
{ eC?/l*gF3
int n = -1; 'w[d^L
try{ $ bNe0
oSavedFile.write(b,nStart,nLen); 51qIo4$
n = nLen; vvAk<[
} "g%:#'5
catch(IOException e) _c8.muQ<
{ #0g#W
e.printStackTrace (); M/a/H=J
} Y@H,Lk
:{:?D\%6
yvWzc uL#
return n; +){a[@S@x
} |Xm4(FN\
`A'I/Hf5
qTHg[sME
} v*~%x
&n]Z1e}5
NB5L{Gf6-
/* o|qeh<2=x
**SiteInfoBean.java ZqbM%(=z(`
*/ .8qzU47E
package NetFox; d=(Yl r
z]l-?>Zbg
;Nf hKu%K
public class SiteInfoBean { y'!p>/%v
~|Ih JzDt
df4^C->:
private String sSiteURL; //Site's URL |g\.5IM#W
private String sFilePath; //Saved File's Path EkStb#
private String sFileName; //Saved File's Name 9hR:y.
private int nSplitter; //Count of Splited Downloading File *KjVPs
J;=aIiN]R
I0l.KiBm
public SiteInfoBean() '5xuT _
{//nSplitter的缺省值为5 ;/";d]j
//default value of nSplitter is 5 ADyNNMcx
this("","","",5); S?nNZW\6[
} 0J:U\S
;%rs{XO9
+wz`_i)!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p*AP 'cR
{ D2TXOPH
sSiteURL= sURL; zfjDb
sFilePath = sPath; EAC(^+15K
sFileName = sName; U-~*5Dd
this.nSplitter = nSpiltter; &Qtp"#{
1(:b{Bl
]*g ss'N
} dS3>q<J*a
SA`J.4yn
w~Tq|kU[
public String getSSiteURL() iO?gF
{ 2w x[D
return sSiteURL; *%Nns',
} '{j\0
$LxG>db
m0BG9~p|
public void setSSiteURL(String value) _cxm}*}\#
{ x;ERRK
sSiteURL = value; PUQ_w
} q*F~~J!P
OUlxeo/
q#Yg0w~
public String getSFilePath() XDP6T"h
{ gfdPx:7^
return sFilePath; r{R[[]p
} R<y Nv
45r]wT(C
`r~`N`o5A
public void setSFilePath(String value) =9DhO7I'
{ fR]p+\#8u*
sFilePath = value; ?8wwd!)x%
} 3ZW/$KP/
Ks49$w<
Y91 e1PsV
public String getSFileName() B%%.@[o,
{ OQytgXED
return sFileName; SQdzEF
} XI%RneuDr:
f"ZqA'KB#
; d, JN
public void setSFileName(String value) a gmeiJT
{ |MOn0*
sFileName = value; 8Z9MD<RLw
} U,%s;
.KT 7le<Zm
S4l)TtY
public int getNSplitter() "B|nhd
{ LCo1{wi
return nSplitter; p<of<YU)
} '|YtNhWZ?
RJtixuvh@
} D/+<
public void setNSplitter(int nCount) -,K*~z.l
{ '\ph`Run
nSplitter = nCount; u4Y6B ]Q
} >Jm-2W5J
} [ E$$nNs
~I8v5 H
MAuM)8_P/|
/* 'sm[CNzS
**Utility.java XsAY4WTS
*/ ^;V}l?J_s
package NetFox; 9O),/SH;:
vbr~<JT=
89*S?C1
public class Utility { G*)s%2c>h
3q'K5} _
&GXtdO>;Zv
public Utility() c+szU}(f6(
{ tpv?`(DDU
q1N4X7<_
Bv;I0i:_
} Q9`s_4
Am2*-
//线程睡眠 DWF >b
public static void sleep(int nSecond) .LX?VD
{ `y1BTe&
try{ !&@2
Thread.sleep(nSecond); `^O'V}T
} bcq@N
catch(Exception e) .(`(chRa}
{ pO\S#GnX
e.printStackTrace (); YEg .
} Ro$j1Aw(
} <$"7~i/X
G i$
//日志 ^bF}_CSE
public static void log(String sMsg) 08`f7[JQo]
{ fy9uLl}h
System.err.println(sMsg); {]+ jL1
} PqTYAN&F
Bfbl#ZkyL
{;U}:Dx
public static void log(int sMsg) @[n2dmj
{ -s{R/6:
System.err.println(sMsg); kJ/+IGV^v
} w#W5}i&x
} 6(:)otz
|__d 8a
j6`6+W=S(
/* %wOOzp`
**TestMethod.java :RPVT,O}
*/ P~&O4['<
package NetFox; baqn7k"
4\v~HFsv
3)dP7rmZ
public class TestMethod { wyp{KIV
',DeP>'%>
EH(tUwY%{
public TestMethod() n:F@gZd`
{ ///xx/weblogic60b2_win.exe 1U
try{ ,bxz]S1W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MdLj,1_T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e,^pMg~
SiteFileFetch fileFetch = new SiteFileFetch(bean); S 9WawI
fileFetch.start(); e!6eZ)l
} %@>YNPD`E
catch(Exception e){e.printStackTrace ();} q5!0\o:
'HCnB]1
k@7kNMl
} =<Hy"4+?.
FWIih5 3`
FZeP<Ban
public static void main(String[] args) 4yhcK&
{ iL+y(]
new TestMethod(); f;R>Pr;rD
} ZH% we
} $kv@tzO
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