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)); 6nc0=~='$
} FW_G\W.
for(int i=0;i<nEndPos.length-1;i++) z9 O~W5-U
{ O)OUy
nEndPos = nStartPos[i+1]; }~rcrm.
} /oFc03d
nEndPos[nEndPos.length-1] = nFileLength; B "*`R!y
} `v~!H\q
} 0D<TF>M;pn
cI3y
7^Na9]PY
//启动子线程 ?d4Boe0-a2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NIaF5z
for(int i=0;i<nStartPos.length;i++) YwGHG{?e
{ ^xt9pa$f
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TMqY4;UeL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ALfiR(!
nStartPos,nEndPos,i); 3^XVQS***
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ka#K [qI
fileSplitterFetch.start(); t}VwVf<K
} 6%E~p0)i%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :\mRtVH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k}HQq_Y(<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vu<#wW*9
nEndPos = " + nFileLength); _|X7 n~
// fileSplitterFetch[nPos.length-1].start(); n08; <
;Xyte
BB63xEx
//等待子线程结束 .9OFryo
//int count = 0; IfMpY;ow=
//是否结束while循环 +1/b^Ac
boolean breakWhile = false; +qhnP$vIe
JD ]OIh
1Fs-0)s8
while(!bStop) 0vn[a,W<A
{ p0Gk j-
write_nPos(); +RS$5NLH
Utility.sleep(500); F?cq'd
breakWhile = true; 5/ * >v
VRF6g|0;
L%XXf3;c
for(int i=0;i<nStartPos.length;i++) ` 5#hjLe
{ ab@=cL~^
if(!fileSplitterFetch.bDownOver) {OCJ(^8i
{ qU-!7=}7
breakWhile = false; (UGol[f<
break; 1Cv#nhmp
} 84^[/d;!
} E MQ4yK
if(breakWhile) ZE rdt:w
break; CU$)QH{
e #M iaX
+I@cO&CY|
//count++; iDw.i"b
//if(count>4) &\^rQi/tf
// siteStop(); U-g9C.
} Xu6K%]i^
036[96t,F
3cixQzb}u
System.err.println("文件下载结束！"); (sCAR=5v\
} I+" lrU
catch(Exception e){e.printStackTrace ();} Yb6q))Y
} /zT`Y=1
6G}c1nWU
h55>{)(E
//获得文件长度 MwAJ(
public long getFileSize() 8teJ*sz
{ .YR8v1Cp
int nFileLength = -1; 'I v_mig
try{ 6,+nRiZ
URL url = new URL(siteInfoBean.getSSiteURL()); B |&F%P0:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #tDW!Xv?
httpConnection.setRequestProperty("User-Agent","NetFox"); Y)Tl<
Kt6>L5:94
c`jDW S
int responseCode=httpConnection.getResponseCode(); % O%xpSYr
if(responseCode>=400) PS@*qTin
{ Ri @`a
processErrorCode(responseCode); 1 i3k
return -2; //-2 represent access is error NR3`M?Hjf
} k':s =IXW
>f$NzJ}
vq>l>as9O
String sHeader; b\giJ1NJB
;LQ9#M?
CGZ^hoh/
for(int i=1;;i++) opD-vDa h
{ bX2"89{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L/i(KF{
//Utility.log(in.readLine()); ARWZ; GX
sHeader=httpConnection.getHeaderFieldKey(i); v{y{sA
if(sHeader!=null) J(s;$PG
{ {G*OR,HN
if(sHeader.equals("Content-Length")) h1f8ktF
{ QDE$E.a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7&+Ys
break; @G*.1;jO
} 5I' d PNf
} QVtM.oi!Q
else "U8S81'
break; ^npJUa
} 1'O0`Me>#
} Im)EDTm$
catch(IOException e){e.printStackTrace ();} zF: j
catch(Exception e){e.printStackTrace ();} Uu'dv#4Iw
<3Gqv9Y&
:=fvZAWD
Utility.log(nFileLength); iM5vrz`n
hs(W;tR@W
;LMWNy4
return nFileLength; Wi$dZOcSJ
} FjFwvO_.
.Dw,"VHP
~xDw*AC-
//保存下载信息（文件指针位置） c-8!#~M(
private void write_nPos() z<&m*0WYA
{ wC` R>)
try{ 1mH\k5xu
output = new DataOutputStream(new FileOutputStream(tmpFile)); SlaDt
output.writeInt(nStartPos.length); zOB=aG?/
for(int i=0;i<nStartPos.length;i++) A'-_TFwW
{ Ik~1:D]f
// output.writeLong(nPos); Fn+?u
output.writeLong(fileSplitterFetch.nStartPos); op@iGC+
output.writeLong(fileSplitterFetch.nEndPos); &leK}je [
} ,}J_:\j
output.close(); 50n}my'2h
} F]_cbM{8/
catch(IOException e){e.printStackTrace ();} a$JLc a
catch(Exception e){e.printStackTrace ();} \ZH&LPAY
} XvKFPr0~
GwLFL.Ke
xs!p|
//读取保存的下载信息（文件指针位置） JhX=l-?
private void read_nPos() ir[jCea,
{ hfrnxeM#~
try{ Uyx&E?SlEq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =yXs?y"
int nCount = input.readInt(); ;t(f1rPyE
nStartPos = new long[nCount]; qf8[!5GM
nEndPos = new long[nCount]; S$[k Q|Am
for(int i=0;i<nStartPos.length;i++) 0rE(p2
{ NlF}{
nStartPos = input.readLong(); 'q{733o
nEndPos = input.readLong(); Vrp[r *V@E
} 'C>U=cE7
input.close(); ]RIVc3?;$
} -]S.<8<$
catch(IOException e){e.printStackTrace ();} \Fb| {6+
catch(Exception e){e.printStackTrace ();} Qe$k3!
} jH*)%n5,\
Q8qz*v]{
=Ho"N`Qy
private void processErrorCode(int nErrorCode) lMifpK
{ h(' )"
System.err.println("Error Code : " + nErrorCode); t"AzI8O
} }!s!;BOx
ycr"Y|
Wa'sZ#
//停止文件下载 0 f/.>1M=
public void siteStop() %2l7Hmp4H
{ uT_!'l$fr
bStop = true; !#x=JX
for(int i=0;i<nStartPos.length;i++) ;#k-)m%
fileSplitterFetch.splitterStop(); q/gB<p9
G/?~\ }:s
R,_d1^|*w
} >e&:`2%.
} SO?8%s(
//负责部分文件的抓取 BNucc']
**FileSplitterFetch.java %NARyz
*/ Qt+:4{He
package NetFox; z/]q)`G
<7sIm^N
K_BPZ5w
import java.io.*; .tXtcf/
import java.net.*; {}Ejt:rKN
yTBS=+X
2eP;[o
public class FileSplitterFetch extends Thread { TprtE.mP
d"Q |I
$2#7D* Rx
String sURL; //File URL NPjv)TN}3
long nStartPos; //File Snippet Start Position SUtf[6
long nEndPos; //File Snippet End Position 0$vj!-Mb^j
int nThreadID; //Thread's ID E~hzh /,34
boolean bDownOver = false; //Downing is over 6oL1_)
boolean bStop = false; //Stop identical Mi7y&~,
FileAccessI fileAccessI = null; //File Access interface #D%ygh=
*cv}*D
u{f* M,k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )Y]/^1hx
{ 5#JJ?
this.sURL = sURL; Q<"[C 1Lj
this.nStartPos = nStart; CAc %f9!3
this.nEndPos = nEnd; eE]hy'{d<
nThreadID = id; ,?-\ x6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &#m"/g7w4N
} !~iGu\y
vS?odqi#n
IB5BO7J
public void run() ;N=G=X|}
{ Ug"rJMZG
while(nStartPos < nEndPos && !bStop) SZ!=`a]
{ [`_io>*g
cma*Dc
-$a>f4]
try{ XhW %,/<
URL url = new URL(sURL); M8;lLcgu.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eE8ULtO
httpConnection.setRequestProperty("User-Agent","NetFox"); )g1a'G
String sProperty = "bytes="+nStartPos+"-"; 3Rv7Qx
httpConnection.setRequestProperty("RANGE",sProperty); x4K`]Fvhl
Utility.log(sProperty); <:;^'x>!
hfM;/
nBLj [
InputStream input = httpConnection.getInputStream(); h{iEZ#
//logResponseHead(httpConnection); ,/Cq v
WE!vSZ3R
'c`jyn
byte[] b = new byte[1024]; vK'?:}~
int nRead; LXfCmc9|Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5\4g>5PD
{ L/r@ S'
nStartPos += fileAccessI.write(b,0,nRead); m:CTPzAt
//if(nThreadID == 1) \E4B&!m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~Gv#iRi>
} \NL+}cL/
b=PVIZ
3smM,fi
Utility.log("Thread " + nThreadID + " is over!"); ":;@Hnb/
bDownOver = true; i6PM<X,{;
//nPos = fileAccessI.write (b,0,nRead); '/%zi,0
} UVuDQ
catch(Exception e){e.printStackTrace ();} )mcEQ-!b
} $17 su')
} JhK/']R
X]*QUV]i
|;vi*u
//打印回应的头信息 oR#:NtX@
public void logResponseHead(HttpURLConnection con) '\DSTr:N
{ HeN~c<NuB
for(int i=1;;i++) v90T{1+M|4
{ &<x@1,
String header=con.getHeaderFieldKey(i); Ukphd$3J=
if(header!=null) qN| fEO>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VHUW]8We
Utility.log(header+" : "+con.getHeaderField(header)); Z@rN_WXx
else &XLD S=j
break; ?w&SW{ I
} /X8<C=}
} 7,$z;Lr0S
|QZ58)>
' P"g\;Ij
public void splitterStop() [IBQvL
{ aw $L$7b}
bStop = true; %:C ]7gQ
} r64u31.)
TCVl8)j
E@)\Lc~
} n-;y*kD
9h,u6e
>`T5]_a
/* p='-\M74K
**FileAccess.java deX5yrvOie
*//文件访问(定位，写) )h$NS2B`
package NetFox; wo^Sy41bF
import java.io.*; (&\aA 0-}H
;e8V +h
_!V%fw
public class FileAccessI implements Serializable{ ^U7OMl4Usq
rnm03 '{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LJzH"K[Gg6
RandomAccessFile oSavedFile; R!x: C!{
long nPos; 76fIC
L#h:*U{@40
vR7HF*8
public FileAccessI() throws IOException B/uniR^x
{ wFn[9_`*
this("",0); l95<QI
} &~sfYW
tx7~SUr
V`hu,Y;%
public FileAccessI(String sName,long nPos) throws IOException e_3CSx8Cc
{ xl4=++pu)
oSavedFile = new RandomAccessFile(sName,"rw"); QP I+y8N=
this.nPos = nPos; ctmQWrk|B
oSavedFile.seek(nPos); u62)QJE
} -#&kYK#Ph
,t$,idcT+
bMoAD.}
public synchronized int write(byte[] b,int nStart,int nLen) d}I(`%%)
{ #&!G"x7
int n = -1; ,2[ra9n
try{ M~T.n)x2
oSavedFile.write(b,nStart,nLen); D vkxI<Xa
n = nLen; TQ :/RT
} d4^`}6@
catch(IOException e) Tp%(I"H'_;
{ pa .K-e)Mu
e.printStackTrace (); sYbH|}
} ?h\mk0[
}k$4/7ri
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return n; S9sR#
} OJ>.-"
Bn wzcl
ik1tidw
} n(Y%Vmy
rx~[Zs+*
5t:8.%<UK
/* <!^ [~`
**SiteInfoBean.java LwJ0
*/ Ps[$.h
package NetFox; eH>#6R1-
"AueLl)
%uESrc-;
public class SiteInfoBean { *e.*=$
;]D(33)(
H6kf K5,
private String sSiteURL; //Site's URL D}mL7d1
private String sFilePath; //Saved File's Path &wH:aD
private String sFileName; //Saved File's Name QOFvsJ<s
private int nSplitter; //Count of Splited Downloading File H:&?ha,9
>O`l8tM
eBW=^B"y+
public SiteInfoBean() %B2XznZ:
{//nSplitter的缺省值为5 P!g-X%ngo
//default value of nSplitter is 5 X~T/qFS
this("","","",5); C"<s/h
} TvhJVVQ+?
my\&hCE
Iq5pAHm>M6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b}z`BRCc
{ 6Y*;{\Rd
sSiteURL= sURL; RNJFSD.
sFilePath = sPath; Va<HU:<
sFileName = sName; jRZ%}KX
this.nSplitter = nSpiltter; 0NE{8O0;Fr
~9o6 W",
|WQ9a' '
} O_,O,1
U..<iNQE5
[IX+M#mf
public String getSSiteURL() f_mhD dq
{ .QWhK|(.!
return sSiteURL; =jAFgwP\
} lP<I|O=z
6DF
Rs;15@t@
public void setSSiteURL(String value) -e-e9uP
{ E0f{iO;}
sSiteURL = value; ?r_kyuU
} fZryG
:J_oj:0r"f
Csst[3V
public String getSFilePath() S\C*iGeqJ
{ _kraMQ>
return sFilePath; "PWl4a&
} nS.G~c|
/MTf0^9
Fe=8O ^\
public void setSFilePath(String value) 9M$/=>^ Z
{ @s*,xHE
sFilePath = value; 3}Xc71|v
} Mhpdaos
/Bv#) -5
y.a]r7
public String getSFileName() 5N/Lk>p1u
{ |Ur"za;%@
return sFileName; >9K//co"of
} n]? WCG}cd
S q@H
w<nv!e?
public void setSFileName(String value) kyUl{Zj
{ gSi5u#}J
sFileName = value; HMQI&Lh=U
} ZW4aY}~)$
mf$j03tu
UsW5d]i}Y
public int getNSplitter() t 0O4GcAN
{ f?UzD#50D
return nSplitter; L10IF
} %_)zWlN
|"7Pv skT
7!4V>O8@
public void setNSplitter(int nCount) >.%4~\U
{ Epjff@7A
nSplitter = nCount; @PkJY
} E%pz9gcSx
} H oy7RC&
RIy\u>
r|Zi3+
/* ]r"Yqv3
**Utility.java Zr/r2
*/ gQVBA %
package NetFox; yY=<'{!
a5c'V
;Rnhe_A.
public class Utility { QApyP CH
BSUPS+@+
.XH8YT42
public Utility() \_ow9vU
{ f6ZZ}lwaV
,@CfVQz
4('JwZw\!
} 8C&x MA^
9C}qVoNu
//线程睡眠 {U @3yB
public static void sleep(int nSecond) &"S/Lt
{ +<(a}6dt
try{ &^QPkX@p
Thread.sleep(nSecond); AlX3Wv}
} :=!Mh}i
catch(Exception e) y?:dE.5p|
{ YMzBAf
e.printStackTrace (); Go8F5a@j
} BQrL7y
} F@SG((`
*@M3p}',M
//日志 %J P!{mqj
public static void log(String sMsg) Da,Tav%b
{ 8 njuDl
System.err.println(sMsg); X#J6Umutm
} \lr/;-zP
(cV
rw u3Nb
public static void log(int sMsg) *o4%ul\3Y|
{ A~71i&
System.err.println(sMsg); {BOLPE-
} rz
} &?<AwtNN
_Z#eS/,O@
~"7J}[i5
/* fPQ|e"?
**TestMethod.java F=Y S^
*/ )/Y~6A9>
package NetFox; f%Ke8'&
UxqWnHH.`
Q1V2pP+=@
public class TestMethod { 5si}i'in
7'.s7& '7
%C*^:\y
public TestMethod() qei$<j'b
{ ///xx/weblogic60b2_win.exe }98-5'u.X
try{ SMO*({/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .ZX2^)`XD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G11cNr>*
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3M*Y= ?pI
fileFetch.start(); [j0w\{
} JMsHK,(
catch(Exception e){e.printStackTrace ();} %zljH"F
n7iE8SK|k
{nRUH*(d9
} I'A:J
eP|)SU
,)$Wm-
public static void main(String[] args) >d%VDjk .
{ Gpu_=9vzv
new TestMethod(); _Ex?Xk
} ] 09yy
} DTy/jaK
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