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)); 3:B4;
} ?ISv|QpC
for(int i=0;i<nEndPos.length-1;i++) %CaF-m=Pq
{ x6iT"\MO
nEndPos = nStartPos[i+1]; ^v+7IFn
} kf-/rC)>
nEndPos[nEndPos.length-1] = nFileLength; j"Y5j B`
} d{FD.eI0
} >XU93 )CX
,!I'0x1OR
Y(97},
//启动子线程 ;)rs#T;$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g@s'-8}X^
for(int i=0;i<nStartPos.length;i++) ,/1[(^e
{ ".|?A9m_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XKEbK\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @7z_f!'u
nStartPos,nEndPos,i); W^T6^q5;H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hphfqdh0`
fileSplitterFetch.start(); Ks/Uyu. X
} G ]JWd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IA(+}V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A1kqWhg\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l ]CnLqf&
nEndPos = " + nFileLength); 2nv-/%]
// fileSplitterFetch[nPos.length-1].start(); #Py\'
y^tp^
\?K>~{)
//等待子线程结束 5Vu@gRk_
//int count = 0; a"pejW`m
//是否结束while循环 uEE#A0
boolean breakWhile = false; yq,%ey8
V+MhS3VD
1}DUe.a
while(!bStop) f<K7m
{ j87IxB?o
write_nPos(); j|c6BdROl
Utility.sleep(500); M\w%c5
breakWhile = true; [*2|#KSCX
maINp"#
%>)&QZig/
for(int i=0;i<nStartPos.length;i++) $ 8WJ$73
{ M hJ;)(
if(!fileSplitterFetch.bDownOver) EVE<LF?
{ d\{a&\v
breakWhile = false; *s}j:fJ
break; +ug[TV
} lV)SOs$
} DNp4U9
if(breakWhile) TkjPa};R
break; |vf /M|
t1%<l
Q"QL#<N
//count++; _>)=c<HL
//if(count>4) z;KUIWg
// siteStop(); -7\6j#;l
} ;DN:AgXP
(g 9G!I
%. -nZC
System.err.println("文件下载结束！"); O,A}p:Pgs
} l0g`;BI_
catch(Exception e){e.printStackTrace ();} Da WzQe=
} /c9%|<O%
1WbawiG}
EHC^ [5
//获得文件长度 #{L !o5
public long getFileSize() R$xkcg2(
{ {V*OYYI`R
int nFileLength = -1; k w]m7T
try{ eHy.<VX
URL url = new URL(siteInfoBean.getSSiteURL()); i<]Y0_?s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #&jr9RB
httpConnection.setRequestProperty("User-Agent","NetFox"); AG==A&d>$
4t;m^Iv
d;c<" +
int responseCode=httpConnection.getResponseCode(); kn1+lF@
if(responseCode>=400) A_\ZY0Xt
{ sJ(q.FRM'
processErrorCode(responseCode); A[.5Bi
return -2; //-2 represent access is error A1u|L^
} ;N/=)m
!s:v UY58
H%:u9DlEK/
String sHeader; <(<19t5.
7h3JH
FeM,$&G:
for(int i=1;;i++) -$J%.fdPs
{ Z" !+p{u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 68v59)0U
//Utility.log(in.readLine()); S3(2.c~
sHeader=httpConnection.getHeaderFieldKey(i); >|e>=
if(sHeader!=null) t<Z)D0.
{ \p&a c&]
if(sHeader.equals("Content-Length")) $3C$])k
{ UIl^s8/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~jqh&u$(
break; =*u:@T=d5
} :%hxg
} ~"ij,Op,3
else +v}R-gNR
break; (KDv>@5
} `Wf)qMb
} Nu%JI6&R
catch(IOException e){e.printStackTrace ();} [@_zsz,`L
catch(Exception e){e.printStackTrace ();} 7:_\t!]
jt/ |u=
RL;>1Q,H
Utility.log(nFileLength); `xO&!DN
]&D;'),
U.@j!UrZ
return nFileLength; yfD)|lK
} D(]])4
N>A*N,+
xedbr
//保存下载信息（文件指针位置） /N>bEr4w
private void write_nPos() bof{R{3q
{ cP~?Iz8nD
try{ 1jhGshhp
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1K;i/
output.writeInt(nStartPos.length); |F'k5Lh
for(int i=0;i<nStartPos.length;i++) 1wqsGad+;
{ oVc l (
// output.writeLong(nPos); )n[ oP%
output.writeLong(fileSplitterFetch.nStartPos); GAlAFsB
output.writeLong(fileSplitterFetch.nEndPos); bh8IF,@a
} 32flOi:
output.close(); sDH|k@K
} ')ErXLP_
catch(IOException e){e.printStackTrace ();} L/.$0@$bv
catch(Exception e){e.printStackTrace ();} mmVx',k
} L|3wGY9E
lj1wTiaI(
"lp),
//读取保存的下载信息（文件指针位置） fi[c^e+IX
private void read_nPos() #6tb{ws3
{ ly d[GfJ
try{ "DFj4XKXY9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tN5brf
int nCount = input.readInt(); 3d{v5. C#X
nStartPos = new long[nCount]; Y.Er!(pz
nEndPos = new long[nCount]; xwH+Q7O&l
for(int i=0;i<nStartPos.length;i++) SRN:!-
{ 35;)O -
nStartPos = input.readLong(); BHwQB2t gc
nEndPos = input.readLong(); T1y,L<7?
} J]f\=;z;<a
input.close(); at/v.U|F
} C_[V[k0(
catch(IOException e){e.printStackTrace ();} <N%8"o
catch(Exception e){e.printStackTrace ();} $FgpFxz;
} .bOueB-
*XmOWV2Y_
Hy<4q^3$G
private void processErrorCode(int nErrorCode) ><X!~by
{ TA}z3!-y*
System.err.println("Error Code : " + nErrorCode); dm Lgt)-t
} A}#@(ma7
Musz+<]
]u_^~
//停止文件下载 yT42u|xZA
public void siteStop() W 9Z.X!h
{ vO1P%)
bStop = true; E5lC'@Dcz
for(int i=0;i<nStartPos.length;i++) $a6&OH/
fileSplitterFetch.splitterStop(); vpY|S2w)Bp
*|x2"?d-F:
-#b-@sD
} icF -`m
} _c|>m4+X
//负责部分文件的抓取 Y"mD)\Bw?
**FileSplitterFetch.java ,>%AEN6N2
*/ J,fXXi)J
package NetFox; y@AKb
C"/]X
Osb"$8im
import java.io.*; G{rUqo
import java.net.*; fV3!x,H
AAsl)
H{x}gBQ
public class FileSplitterFetch extends Thread { unmuY^+<
l%"eQ
`}F=Zjy
String sURL; //File URL 0+O)~>v
long nStartPos; //File Snippet Start Position J-fU,*Bk
long nEndPos; //File Snippet End Position YE5v~2
int nThreadID; //Thread's ID o(~>a
boolean bDownOver = false; //Downing is over :&`Yz
boolean bStop = false; //Stop identical c3|;'s
FileAccessI fileAccessI = null; //File Access interface yov:JnWo
[^W4%S
_c%]RE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UJoWTx
{ F5%-6@=
this.sURL = sURL; 3vOI=ar=L~
this.nStartPos = nStart; qTiUha9
this.nEndPos = nEnd; C%v@u$N
nThreadID = id; -(>x@];r0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ##,i<
} 4aAr|!8|h!
d {moU\W
C9Fc(Y?_
public void run() G#Z%jO-XN
{ 2s EdN$O
while(nStartPos < nEndPos && !bStop) Xt'R@"H<V9
{ Tm_vo-
f9D7T|J?10
&I?1(t~hT
try{ ?4q6>ipx
URL url = new URL(sURL); 96vv85g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3OFv_<6
httpConnection.setRequestProperty("User-Agent","NetFox"); ;4F[*VF!w
String sProperty = "bytes="+nStartPos+"-"; <HG~#oBRq
httpConnection.setRequestProperty("RANGE",sProperty); m0F-[k3)
Utility.log(sProperty); `S<uh9/
(H+'sf^h
K;-:C9@
InputStream input = httpConnection.getInputStream(); ;oC85I
//logResponseHead(httpConnection); -MHu BgYJ-
gSu+]N
Np|iXwl1
byte[] b = new byte[1024]; e\.|d<N?
int nRead; e?L$RY,7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i(,R$AU
{ K]@^8e$(
nStartPos += fileAccessI.write(b,0,nRead); Q%QpG)E
//if(nThreadID == 1) X!,Ngmw.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4cJ7.Pez
} VQ<Z`5eV
`X^4~6/q
[fR<#1Z
Utility.log("Thread " + nThreadID + " is over!"); yN~=3b>
bDownOver = true; "6pjkEt4
//nPos = fileAccessI.write (b,0,nRead); GG;M/}E9
} .6$ST Ksr
catch(Exception e){e.printStackTrace ();} u|8`=
} pa+^5N
} X~G"TT$)
x`%;Q@G
tq@<8?
//打印回应的头信息 DfV_08
public void logResponseHead(HttpURLConnection con) Z#>k:v
{ 5yxZ 5Ni!
for(int i=1;;i++) H7#RL1qM&
{ $z@e19gT
String header=con.getHeaderFieldKey(i); Ks X@e)8u
if(header!=null) j@kBCzX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e@0wF59
Utility.log(header+" : "+con.getHeaderField(header)); 9S6vU7W
else Fw"~f5O
break; s/sH",
} LC[,K
} M?$-u
\|j`jsq
a+weBF#Z
public void splitterStop() PU?kQZU~)
{ kHz3_B9[
bStop = true; iyH<!>a
} rIge6A>I
*i%!j/QDAP
348Bu7':
} &R*d/~SU
NZeIqhj
}(M<sEK~
/* {,s:vPoiA
**FileAccess.java 'Q(A5zfN]Y
*//文件访问(定位，写) fhfdNmtR)I
package NetFox; zq4mT;rqz
import java.io.*; Cn28&$:J
L<8y5B~W
<hy>NM@$
public class FileAccessI implements Serializable{ s|,gn5
X[Y!=e4z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]vT
RandomAccessFile oSavedFile; 4f"be
long nPos; VIi|:k
L1rov
msY"Y*4
public FileAccessI() throws IOException Vaq=f/
{ #M`ijN!Y
this("",0); 3<JZt.|
} 1uXtBk6
Nb]qY>K
YuPgsJ[m
public FileAccessI(String sName,long nPos) throws IOException *[yCcqN.
{ YT:<AJm
oSavedFile = new RandomAccessFile(sName,"rw"); wc__g8?'
this.nPos = nPos; C7+TnJ
oSavedFile.seek(nPos); k9R1E/;
} 1Tiq2+hmf
pd7FU~-
:hJhEQH(9
public synchronized int write(byte[] b,int nStart,int nLen) ]E=JUYf0
{ oTx#e[8f{
int n = -1; lc5NC;JR
try{ N(1jm F
oSavedFile.write(b,nStart,nLen); a-QHm;_S
n = nLen; o@pM??&x
} Rut6m5>
catch(IOException e) u5R^++
{ j/Bzbjq"
e.printStackTrace (); 5@Py`
} Nr(WbD[T
,#WXAAmm
3!}'A
return n; !%@n067
} bJBx~
3`e1:`Hu
IRS^F;)
} }qlz^s
1.>sG2*P
YKM(qh2
/* {L4^IKI
**SiteInfoBean.java >nr1|2
*/ {g )kT_
package NetFox; Vq<|DM3z<
0q`'65 lx
R2~Rqlti
public class SiteInfoBean { BAKfs/N
qx!IlO
WHpbQQX
private String sSiteURL; //Site's URL #K)HuT
private String sFilePath; //Saved File's Path /5J! s="
private String sFileName; //Saved File's Name R jAeN#,?
private int nSplitter; //Count of Splited Downloading File ;TW@{re
,2kWj7H%7
+ubO-A?
public SiteInfoBean() 9f"6Jw@F
{//nSplitter的缺省值为5 ;\&7smE[
//default value of nSplitter is 5 ,5L&$Q6
this("","","",5); Y0eu^p)
} }'X}!_9w>
`$#64UZ>U1
-#Wc@\;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <N`rcKE%~P
{ =8J\;h
sSiteURL= sURL; hQet?*diU
sFilePath = sPath; 6Q wL
sFileName = sName; `zsKc 6%
this.nSplitter = nSpiltter; .#Sd|C]R7
8;Pdd1GyUL
(ZI&'"H
} cdGl[dQ/
0 /H1INve
mV4} -
public String getSSiteURL() W%$p,^@S5
{ 'Klz`)F
return sSiteURL; d5],O48A
} .g|pgFM?
om/gk4S2
Xg%zE
public void setSSiteURL(String value) 2]C0d8=*?
{ W&yw5rt**
sSiteURL = value; 4Fz^[L}[
} )O+9v}2
5GRN1Aov<
@rJ#Dr
public String getSFilePath() k~hL8ZT[
{ > voUh;L
return sFilePath; Z'fy9
} zf S<X
eVlI:yqppj
HL!-4kN <$
public void setSFilePath(String value) x)GoxH~#
{ #IXQ;2%E
sFilePath = value; [ z&y]~
} }0!\%7-Q
8t7hN?,t
9GGBJTk-
public String getSFileName() &#)3v8
{ c,-< 4e
return sFileName; nh8h?&q|
} ]v#T'<Nl
6zI?K4o
L_A|
public void setSFileName(String value) TfxKvol'
{ 3)eeUO+
sFileName = value; "vJADQ4F
} Nyo6R9^
vLC&C-f
>\i{,F=U7
public int getNSplitter() 0-#ct1-
{ {C6Yr9
return nSplitter; [AGm%o=)
} REsThB
ofi']J{R
g 08 `=g
public void setNSplitter(int nCount) iy4JI,-W
{ (;M"'.C
nSplitter = nCount; Vw#07P#A
} WFdS#XfV
} lWdE^-
tDwXb>
'-~86Q
/* KA<
**Utility.java H_2hr[
*/ <zUmcZ
package NetFox; *X>rvAd3
[v&_MQ
*%8us~w5/
public class Utility { $C>EnNx
9Z*vp^3
N;hq
public Utility() @s[bRp`gd
{ XR&*g1
`2Z=Lp
{P3,jY^
} h'}5"m
:G`_IB\
//线程睡眠 rm cy-}e
public static void sleep(int nSecond) 0O:TKgb&C.
{ )I<.DN&
try{ Jw^+t)t
Thread.sleep(nSecond); V:+}]"yJ,
} X >**M
catch(Exception e) {u1t.+
{ r*$"]{m}
e.printStackTrace (); +`4|,K7'
} y^XwJX-f
} N7;2BUIXJ
*?8Q:@:
//日志 Pf!K()<uJ
public static void log(String sMsg) w9oiu$7),
{ qzLRA.#f^
System.err.println(sMsg); X}Csl~W8in
} byMO&Lb*
r9%W?fEBp
_Nj;Ni2rD
public static void log(int sMsg) f(C0&"4e
{ h>n;A>k@N
System.err.println(sMsg); }Yt0VtLt
} " c]Mz&z
} 3HA{18{4uP
dYsqF 3f
\i&yR]LF
/* EbW7Av
**TestMethod.java s)L7o)56/
*/ }Bb(wP^B.
package NetFox; g7H;d
J^W.TM&q$,
1idEm*3&(
public class TestMethod { :{fsfZXXr
q4Z\y
<O*q;&9
public TestMethod() !1l2KW<be
{ ///xx/weblogic60b2_win.exe dfrq8n]
try{ }l/md/C0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EmH{G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ucn aj|
SiteFileFetch fileFetch = new SiteFileFetch(bean); hZFbiGQr\
fileFetch.start(); !pN,,H6Y
} X3"V1@-i4$
catch(Exception e){e.printStackTrace ();} mA4v 4z
Sb`>IlT\#
"<&F=gV
} PaZFM
Qj=l OhM
R_*\?^k|A
public static void main(String[] args) "L,FUo^&
{ _ 9k^Hd[L$
new TestMethod(); W$3p,VTMmB
} ?T^$,1-
} 6^zv:C%
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