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)); [(3s5)O
} *@PM,tS;
for(int i=0;i<nEndPos.length-1;i++) {]}94T~/k
{ 7mdd}L^h Z
nEndPos = nStartPos[i+1]; #>bj6<
} M$Z2"F;
nEndPos[nEndPos.length-1] = nFileLength; t>?tWSNf
} *n EkbI/
} 4LB8p7$|a3
^5Lk}<utw
UsFn!!+
//启动子线程 .S-)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m Rw0R{
for(int i=0;i<nStartPos.length;i++) EV{Ys}3M
{ (oX!D(OI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 54z.@BJhE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J@$~q}iG
nStartPos,nEndPos,i); OHpV%8`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :yD>Tn;1
fileSplitterFetch.start(); HLwMo&*rA
} 'n,V*9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bz#]>RD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =iKl<CqI$E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1VM2CgRa
nEndPos = " + nFileLength); 9!uiQ
// fileSplitterFetch[nPos.length-1].start(); fM"*;LN!N
=s4(Y
Lm2!<<<
//等待子线程结束 3rKJ<(-2/
//int count = 0; ]'(D*4
//是否结束while循环 %2zmc%]r
boolean breakWhile = false; =gQ9>An
~o%igJ }.C
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while(!bStop) HVHv,:bPo
{ }/vW"&h-
write_nPos(); Yjjh}R#
Utility.sleep(500); I6f/+;E
breakWhile = true; m]AT-]*f
edq,:
eyyME c!
for(int i=0;i<nStartPos.length;i++) esnq/
{ mvZ#FF1,J
if(!fileSplitterFetch.bDownOver) *$vH]>)p
{ *|dr-e_j
breakWhile = false; }Rw,4
break; .M^[/!
} tWIJ,_8l
} ciS,
if(breakWhile) =zyA~}M2
break; <R /\nYXz
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2Ckx.m&
//count++; HTOr
//if(count>4) m<-ShRr*b
// siteStop(); , [|aWT%9
} z6ObX
-U=Ci
@9B*V~ <
System.err.println("文件下载结束！"); dg24h7|]
} erUYR"
catch(Exception e){e.printStackTrace ();} aE`d[dSG
} +GI906K
Q< :RLKVT
R{H[< s+n
//获得文件长度 R2Fjv@Egk
public long getFileSize() D=#RQ-
{ $0 olqt:
int nFileLength = -1; 4D0jt$==
try{ uX6yhaOp|
URL url = new URL(siteInfoBean.getSSiteURL()); LTTMa-]Yy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {p84fR1P
httpConnection.setRequestProperty("User-Agent","NetFox"); tR|dnC4U
a]T:wUYG'
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int responseCode=httpConnection.getResponseCode(); Kgu8E:nL
if(responseCode>=400) sCFxn
{ i3,IEN
processErrorCode(responseCode); Mqr_w!8d
return -2; //-2 represent access is error !5o j~H
} e|\xFV=4
IW0S*mO$
i7Up AHd/
String sHeader; }uZs)UQ|$
/kbU<
S<"Fp1#"l
for(int i=1;;i++) aj1]ZT\
{ V95o(c.p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cKt=?
//Utility.log(in.readLine()); B{nwQC b
sHeader=httpConnection.getHeaderFieldKey(i); >qmCjY1
if(sHeader!=null) ;miif
{ Q\N*)&Sd<M
if(sHeader.equals("Content-Length")) +i&<`ov
{ Q7_5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3f[Yk#"
break; .S/5kLul
} o.{W_k/n
} 6Wu*zY_+
else e73=*~kfR
break; 8W\yM;'
} _}R[mr/
} 4dX{an]Cz
catch(IOException e){e.printStackTrace ();} X7},|cmD_
catch(Exception e){e.printStackTrace ();} mM,HMrgLqK
).SJ*Re*^I
k QuEG5n.-
Utility.log(nFileLength); R~\R>\
Jb QK$[z"
ZZY#.
return nFileLength; ]M7FIDg
} (~GQncqa
F8f}PV]b
h'y%TOob
//保存下载信息（文件指针位置） X-c|jn7
private void write_nPos() Y![Q1D!
{ XQ#K1Z
try{ v>8C}d^
output = new DataOutputStream(new FileOutputStream(tmpFile)); OETo?Wg1Z
output.writeInt(nStartPos.length); J}#gTG( '
for(int i=0;i<nStartPos.length;i++) ?=? _32O
{ >'*%wf[{
// output.writeLong(nPos); 6 c_#"4
output.writeLong(fileSplitterFetch.nStartPos); -s3`mc}*
output.writeLong(fileSplitterFetch.nEndPos); xZ'fer`&
} 'C1lP)S5
output.close(); Q^(CqQo!<
} P.Z:`P)
catch(IOException e){e.printStackTrace ();} \}Jznzx;
catch(Exception e){e.printStackTrace ();} !dLu($P
} 2J7|y\N,
?jmP]MM
DrK]U}3fh"
//读取保存的下载信息（文件指针位置） 1q6)R/P
private void read_nPos() jn<?,UABD
{ uX_H;,n
try{ o(*\MTt?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~g{j)"1
int nCount = input.readInt(); *~vB6V|1
nStartPos = new long[nCount]; v:t;Uk^Y
nEndPos = new long[nCount]; M3tl4%j
for(int i=0;i<nStartPos.length;i++) a:BW*Hy{\
{ IO\l8G
nStartPos = input.readLong(); ^A$=6=CX
nEndPos = input.readLong(); DrJ?bG;[
} m$T5lKn}U?
input.close(); }"D;?$R!
} ?I}RX~Tgg
catch(IOException e){e.printStackTrace ();} G:AA>t
catch(Exception e){e.printStackTrace ();} 5\Q Tm;
} p*;!5;OUR
?qgQ)#6
3s6obw$ki
private void processErrorCode(int nErrorCode) }`uyOgGg*
{ Q5,zs_j
System.err.println("Error Code : " + nErrorCode); cOVj @z
} yHeL&H
J p'^!
{L-^J`> G
//停止文件下载 O^L]2BVC
public void siteStop() ;wn9 21r
{ pY31qhoZ.
bStop = true; `YNzcn0x
for(int i=0;i<nStartPos.length;i++) Sdu\4;(
fileSplitterFetch.splitterStop(); #])"1fk
bb6x} jR
(GJtTp~2C4
} gv*b`cl
} OoB|Eh|),
//负责部分文件的抓取 }y(t')=9
**FileSplitterFetch.java IW~R{ ]6
*/ TM)INo^
package NetFox; j4$nr=d.6
PLCm\Oh$l
Na0^csPm
import java.io.*; +kL7"
import java.net.*; r w?wi}}gn
6jq*lnA%
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public class FileSplitterFetch extends Thread { IZZAR
(i~UH04r>s
c4H6I~2Na
String sURL; //File URL /Hr|u
long nStartPos; //File Snippet Start Position B2;P%B
long nEndPos; //File Snippet End Position `16'qc
int nThreadID; //Thread's ID 1j?P$%p
boolean bDownOver = false; //Downing is over Y~"tL(WfJl
boolean bStop = false; //Stop identical _*mn4n=
FileAccessI fileAccessI = null; //File Access interface P5Xp #pa
AyE*1 FD
.S k+"iH5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "Z.6@ c7
{ p{Lrv%-j
this.sURL = sURL; ynIe4b
this.nStartPos = nStart; ]A5F}wV4
this.nEndPos = nEnd; ha :l-<a
nThreadID = id; 7HPwlS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jSI1tW8
} fn}E1w
~+Wx\:TT
vjEDd`jYZ
public void run() Mu3G/|t(
{ , $7-SN
while(nStartPos < nEndPos && !bStop) WVP?Ie8
{ "N+4TfXy
25X|N=}
7-744wV}Z
try{ Kb;*"@LX
URL url = new URL(sURL); WtOjPW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o,7|=.-b
httpConnection.setRequestProperty("User-Agent","NetFox"); T?8BAxC?K
String sProperty = "bytes="+nStartPos+"-"; _XZ Gj:V
httpConnection.setRequestProperty("RANGE",sProperty); f"Sp.'@
Utility.log(sProperty); 0#V"
Y@FYo>0O
\BHZRytQF
InputStream input = httpConnection.getInputStream(); ,rB(WKU
//logResponseHead(httpConnection); [ V.67_~
OyO<A3
/~,*DH$)
byte[] b = new byte[1024]; }B0[S_mw
int nRead; <"3q5ic/Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .j4y0dh33
{ 72nZ`u
nStartPos += fileAccessI.write(b,0,nRead); )tlj{ 7p
//if(nThreadID == 1) iv*RE9?^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pwo$qs(p
} ex>7f%\
9\8ektq}Z
R27'00(Z0
Utility.log("Thread " + nThreadID + " is over!"); `l|Oj$
bDownOver = true; oCT,v0+4O
//nPos = fileAccessI.write (b,0,nRead); zyPb\/
} Wl| i$L)7
catch(Exception e){e.printStackTrace ();} $}/tlA&e
} 7Z>vQf B
} >CvhTrPI
ka_m Q<{9
#9GfMxH
//打印回应的头信息 ?`RlYu
public void logResponseHead(HttpURLConnection con) /pF8S!,z
{ rN1]UaT
for(int i=1;;i++) ;hQ[-
{ By1Tum+I1
String header=con.getHeaderFieldKey(i); ilL%
if(header!=null) ^Gk)aX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Cu@q*:'
Utility.log(header+" : "+con.getHeaderField(header)); , Q0Y} )
else ?`+VWa[,e
break; \GEz.Vb
} :!Ci#[g
} (wu'FFJp#
Kw-<o!~
Ta[2uv>
public void splitterStop() It3k#A0
{ k]ZE j/y~
bStop = true; ;1&"]N%
} ! $JX3mP
gP>pbW_
C@a I*+@-"
} Ou[`)|>
DN%}OcpZ
ZX/FIxpy
/* HzM\<YD
**FileAccess.java pCt2-aam
*//文件访问(定位，写) i ;B^I8
package NetFox; 5WI bnV@
import java.io.*; fr~Eb'8
O _9r-Zt^
$~5H-wJ
public class FileAccessI implements Serializable{ 1gK|n
)M;~j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0er|QC
RandomAccessFile oSavedFile; p@pb[Bx~[
long nPos; +pYgh8w@
6aB]&WO1@
&0kr[Ik.
public FileAccessI() throws IOException 7c\W&ZEmb-
{ A.*e8a/6X
this("",0); Rxdj}xy
} WWSycH ?[
tQ@7cjq8bA
e (]]
public FileAccessI(String sName,long nPos) throws IOException 3?D, Wu
{ < }K9 50
oSavedFile = new RandomAccessFile(sName,"rw"); ]sEuh~F
this.nPos = nPos; ;BuMzG:tmZ
oSavedFile.seek(nPos); &en2t=a
} |kZ!-?9Z
gq?O}gVD
)VQ[}iT
public synchronized int write(byte[] b,int nStart,int nLen) UXji$|ET6
{ DOu^
int n = -1; igL5nE=n
try{ oI#TjF
oSavedFile.write(b,nStart,nLen); +788aK,{#
n = nLen; =w`Mc\o"
} 6W_:w
catch(IOException e) |6^a[x3/U
{ Xr^ 5Th\
e.printStackTrace (); rhLhFN{h
} @(L}:]{@
RF*>U a
rOOo42YW`
return n; ]]y>d!
} !RJ@;S
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l!}gWd,H
} AyQ5jkIE^{
vRtERFL
9+ Mj$
/* MP}-7UA#K
**SiteInfoBean.java P,ZQ*Ju
*/ oaha5aWH
package NetFox; >3&
O-[YU%K3?
F3V:B.C
public class SiteInfoBean { }c||$
cAN8'S(s1
n',7=~
private String sSiteURL; //Site's URL wmV=GV8 d
private String sFilePath; //Saved File's Path MMk9rBf
private String sFileName; //Saved File's Name 2Bi]t%<{
private int nSplitter; //Count of Splited Downloading File i-w<5pGnf
lZ5-lf4
^XeJZkLEB
public SiteInfoBean() ^5MM<73
{//nSplitter的缺省值为5 Z:^<NdKe
//default value of nSplitter is 5 _3W .:
this("","","",5); EwcFxLa!F
} rmBzLZ}
)0I-N)
uxdB}H,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q2|x$5
{ t ^>07#z
sSiteURL= sURL; u gRyUny
sFilePath = sPath; Q~"Lyy8
sFileName = sName; /Q W^v;^
this.nSplitter = nSpiltter; DNj<:Pdd)
$'}|/D
Q65M(x+oy
} B t3++ Mj
OLF6["0Rn
~tTa[_a!
public String getSSiteURL() A'![*O
{ ?lqqu#;8
return sSiteURL; L$a{%]I
} ~YNzSkz
Tq*<J~-
JoB-&r}\V*
public void setSSiteURL(String value) | #a{1Z)
{ 3v$n}.
sSiteURL = value; !M}-N
} ?!F<xi:
+?t& 7={~
zxs)o}8icO
public String getSFilePath() `r&Ui%fk;0
{ ?r]0%W^
return sFilePath; )w}'kih
} S&=@Hj-
ZH=Bm^
T+0z.E!~I
public void setSFilePath(String value) I_Z?'M
{ g<F+Ldgj
sFilePath = value; I|bX;l
} RKMF?:
41B.ZE+*qd
VwBw!,%Ab
public String getSFileName() ?l[#d7IB
{ [$$R>ELYQ
return sFileName; ;E{@)X..|
} 'M?pg$ta_V
U4a8z<l$
FME,W&_d
public void setSFileName(String value) MC-Z6l2
{ {>64-bU
sFileName = value; 5y='1s[%
} U3aM^
j^Qk\(^#IV
/Re67cMQ*
public int getNSplitter() \4G9fR4
{ zB7^L^Y
return nSplitter; R))4J
} ~yngH0S$[b
Zq: }SU
W }Ll)7(|T
public void setNSplitter(int nCount) -NzOX"V]3
{ ^755LW
nSplitter = nCount; @VND}{j
} }!*|VdL0
} nRHlHu
&f A1kG%
u,@ac[!vP
/* va(6?"9
**Utility.java $^e_4]k
*/ p&xj7qwp@F
package NetFox; SRHD"r^@
/a$Zzs&xs
#~rQ\A!4
public class Utility { ,o `tRh<
,rY}IwMw
HA$7Q~{N-t
public Utility() _=[pW2p
{ E^w0X,0XlE
0ikA@SAq
: @gW3'
} e=tM=i"
Z0~,cO8~
//线程睡眠 ev7A;;
public static void sleep(int nSecond) sV%=z}n=
{ FD8
try{ ,ueA'GZ
Thread.sleep(nSecond); 1?TgI0HS
} C3<_0eI
catch(Exception e) .(Z^[C}
{ g]b%<DJ
e.printStackTrace (); m KKa0"
} :h0!giqoQ
} *MWI`=c
sWq}/!@&
//日志 ]VN1Y)
public static void log(String sMsg) .D=#HEshk
{ MA 6uJT
System.err.println(sMsg); odvUU#l
} Hc0V4NHCaL
P6'0:M@5
*:chN' <
public static void log(int sMsg) ,+5!1>\
{ AUU(fy#<
System.err.println(sMsg); 1ww~!R
} {mHxlG)
} >BMtR0
-,"eN}P^
lb)i0`AN+
/* *ul-D42!U
**TestMethod.java !NhVPb,
*/ DC$x}1
package NetFox; %(1y
i+Xb3+R
\D! I"mr
public class TestMethod { !;U}ax;AF
1i|5ii*vc
n*qn8Dq
public TestMethod() G7HvA46
{ ///xx/weblogic60b2_win.exe 4=;`\-7!
try{ CakB`q(8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {<Vw55)#0Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h`:gMhn
SiteFileFetch fileFetch = new SiteFileFetch(bean); }4*~*NoQ
fileFetch.start(); e({-.ra
} _4t
catch(Exception e){e.printStackTrace ();} k'd=|U;(FV
9\R+g5
v$|cF'yyF=
} F)tcQO"G
5lm>~J!/^
qP[jtRIN
public static void main(String[] args) y-:d`>b>\
{ (Mt-2+"+
new TestMethod(); f@xjNm*'Z
} &m@DK>
} v}"DW?
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