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)); <I7UyCAF
} & )Z JT.S
for(int i=0;i<nEndPos.length-1;i++) P;h/)-q8
{ QJxcH$
nEndPos = nStartPos[i+1]; ~*&_zPTN
} Mb-C DPT
nEndPos[nEndPos.length-1] = nFileLength; 27)$;1MT:
} hsi#J^n{
} f"/NY6
cOIshT1
x\)-4w<P
//启动子线程 tP`,Egf"g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N52N ^X>
for(int i=0;i<nStartPos.length;i++) p< XjiRq
{ H}A67J9x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !r$/-8b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~s+\Y/@A
nStartPos,nEndPos,i); kIQMIL0+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B<i1UJ5
fileSplitterFetch.start(); GZ9XG">
} o)w'w34FCT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =*t)@bn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Dp>/lkk.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8I JFQDGA9
nEndPos = " + nFileLength); ?'^xO:
// fileSplitterFetch[nPos.length-1].start(); a93Aj
&}6=V+J;
[<6ez;2q'
//等待子线程结束 ^,,|ED\M{m
//int count = 0; *PD7H9m
//是否结束while循环 |ML|P\1&V
boolean breakWhile = false; B\BP:;"
/1Ndir^c
k: D<Q
while(!bStop) 0&zp9(G5
{ -K PbA`j+
write_nPos(); ,9=5.+AJ
Utility.sleep(500); ZfoI7<?33
breakWhile = true; @r=O~x
T2GJoJ!
T=9+
for(int i=0;i<nStartPos.length;i++) TtlZum\
{ 90(JP-
if(!fileSplitterFetch.bDownOver) tK1P7pbC8r
{ kowBB0
breakWhile = false; _A1r6
break; Z+JPxe#7
} _>0I9.[5
} @}qMI
if(breakWhile) qo/`9%^E?
break; ZE#A?5lb
s@V4ny9x
+uLl3(ml
//count++; ,x&T8o/a
//if(count>4) V-IXtQR
// siteStop(); ?`lIsd
} )$XcO]
Gg8F>y<[R
Gu-6~^Km9
System.err.println("文件下载结束！"); "`s{fy~mV
} Bz!SZpW(M
catch(Exception e){e.printStackTrace ();} M*$#j|
} 6C7|e00v
/'O? 8X<
7a\at)q/y
//获得文件长度 K+p7yZJ
public long getFileSize() \2#7B8
{ ~nDbWv"
int nFileLength = -1; bdbTK8-
try{ Lk#8G>U
URL url = new URL(siteInfoBean.getSSiteURL()); a'r8J~:jy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EIug)S~
httpConnection.setRequestProperty("User-Agent","NetFox"); clyZD`*
eaB6e@]@
fAYp\k
int responseCode=httpConnection.getResponseCode(); OiI29
if(responseCode>=400) )&Af[mS
{ 'ioX,KD
processErrorCode(responseCode); yGj'0c::
return -2; //-2 represent access is error Z}$wvd
} 2Kwr=t
OXDEU.
pV[SY6/
String sHeader; #:[^T,YD0
Tg/?v3M88
!A":L0[7n
for(int i=1;;i++) 4fSGc8
{ x<d2/[(}mT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cb82k[L6
//Utility.log(in.readLine()); q[}W&t,
sHeader=httpConnection.getHeaderFieldKey(i); q!f'?yFYK
if(sHeader!=null) uidoz f2}
{ vLI'Z)\
if(sHeader.equals("Content-Length")) CT{mzC8
{ A9Kt^HR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o3C GG
break; xlIVLv6dO
} "*8>` 6E
} &a8%j+j
else R/EpfYOX
break; JIatRc?g
} Fa0Fl}L
} FeL!%z
catch(IOException e){e.printStackTrace ();} s+0n0C
catch(Exception e){e.printStackTrace ();} adY ,Nz
=j^>sg]
,Jrm85oG
Utility.log(nFileLength); 1$_|h@
0g'MFS
SDu%rr7sQ
return nFileLength; _J&IL!S2
} ROi_k4Fj
q"0_Px9P
^^z_[Ih
//保存下载信息（文件指针位置） o)WzZ,\F^J
private void write_nPos() F]GX;<`
{ `D $ "K1u
try{ kF-7OX0)
output = new DataOutputStream(new FileOutputStream(tmpFile)); VXPsYR&
output.writeInt(nStartPos.length); yYH>~,
for(int i=0;i<nStartPos.length;i++) 3w&Z:<
{ _a\$uVZ
// output.writeLong(nPos); d1}cXSQ1T
output.writeLong(fileSplitterFetch.nStartPos); yk0^m/=C(
output.writeLong(fileSplitterFetch.nEndPos); -&h<t/U
} @yNCWa~N
output.close(); (j&7`9<5
} \2Yo*jE}
catch(IOException e){e.printStackTrace ();} &ox5eX(
catch(Exception e){e.printStackTrace ();} .R^q$U~v3
} a(_3271
|Hv8GT
eIcIl2
//读取保存的下载信息（文件指针位置） W~& QcSWqD
private void read_nPos() (V>/[Ev
{ 'tDVSj
try{ DD'RSV5]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,8.zbr
int nCount = input.readInt(); LIRL`xU7
nStartPos = new long[nCount]; Og1Hg B3v
nEndPos = new long[nCount]; wV q4DE
for(int i=0;i<nStartPos.length;i++) H<Zs2DP`
{ v*&WqVg
nStartPos = input.readLong(); #]2,1dJ
nEndPos = input.readLong(); "y-/ 9C
} i\zN1T_
input.close(); PEMuIYm$
} Z8:'_#^@a[
catch(IOException e){e.printStackTrace ();} DI\^&F)3T2
catch(Exception e){e.printStackTrace ();} e@DVf
} qf*e2"~v
\tfhF#'
FTh/1"a
private void processErrorCode(int nErrorCode) /mQ9}E4X
{ Mb+CtI_'
System.err.println("Error Code : " + nErrorCode); \eCQL(_
} pAH9
^}4ysw
Es&'c1$^s
//停止文件下载 jN%+)Kj0C)
public void siteStop() KV|ywcGhT
{ pW5PF)([
bStop = true; yb-/_{Y
for(int i=0;i<nStartPos.length;i++) "uU[I,h
fileSplitterFetch.splitterStop(); TnLblkX
?>iZ){0,
e ls&_BPE
} v]m#+E
} Ip*[H#h
//负责部分文件的抓取 ~p$ncIr2Q
**FileSplitterFetch.java 2KSt4oa
*/ GI/4<J\
package NetFox; }J] P`v
]*\<k
'p4b8:X
import java.io.*; l 5z8]/
import java.net.*; D}K/5iU]a
?v Z5 ^k
6EkD(w
public class FileSplitterFetch extends Thread { fZt3cE\
n4G53+y'
>}B~~C;
String sURL; //File URL .iH#8Z
long nStartPos; //File Snippet Start Position l&m'?.gf
long nEndPos; //File Snippet End Position Clzz!v
int nThreadID; //Thread's ID ppPzI,
boolean bDownOver = false; //Downing is over >Av%[G5=h#
boolean bStop = false; //Stop identical }$1Aw%p^
FileAccessI fileAccessI = null; //File Access interface ^g*/p[
*,oZ]!
fSzX /r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^<nN~@j
{ \ /6m
this.sURL = sURL; eO=!(
this.nStartPos = nStart; U-GV^j
this.nEndPos = nEnd; 91bJ7%
nThreadID = id; pd X"M>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?u8vK<2h
} 8v']>5S]#
c}g:vh
sTGe=}T8
public void run() b{Kw.?85
{ 7<c&)No;
while(nStartPos < nEndPos && !bStop) {T[/B"QZG
{ -Fs^^={Q
b3!,r\9V
\|9KOulr
try{ B^G{k3]t
URL url = new URL(sURL); ?#X`Eu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nW (wu!2
httpConnection.setRequestProperty("User-Agent","NetFox"); iiZK^/P$
String sProperty = "bytes="+nStartPos+"-"; P=9Zm
httpConnection.setRequestProperty("RANGE",sProperty); dSBW&-p
Utility.log(sProperty); n"{oj7E0a
c~UYs\
-/#tQ~{gs
InputStream input = httpConnection.getInputStream(); o$r]Z1
//logResponseHead(httpConnection); Zm@ O[:~
^y"$k
N:@C% UW}
byte[] b = new byte[1024]; Cz_chK4
int nRead; 6\9 9WQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;{inhiySN
{ ')w*c
nStartPos += fileAccessI.write(b,0,nRead); mckrR$>
//if(nThreadID == 1) S,,3h0$X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <P3r}|K
} %.R_[.W
~4iIG}Y<
1H_#5hd
Utility.log("Thread " + nThreadID + " is over!"); {q:o}<-L+
bDownOver = true; 0Fh*8a}?b
//nPos = fileAccessI.write (b,0,nRead); bMD'teJ
} %?EOD=e=
catch(Exception e){e.printStackTrace ();} 8D:{05
} #={L!"3?e
} 0ZV)Y<DJ
Zh.fv-Ecp
97Qng*i
//打印回应的头信息 hqY9\,.C
public void logResponseHead(HttpURLConnection con) (r.{v@h,dV
{ 5b[:B~J
for(int i=1;;i++) 6Bp{FOj:Ss
{ L&'0d$Tg8
String header=con.getHeaderFieldKey(i); K`FgU7g{
if(header!=null) k[Iwxl;/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~&~%qu
Utility.log(header+" : "+con.getHeaderField(header)); D.<CkDB
else 0{Kl5>Z9M
break; dTaR8i
} 7`tnoTUv
} 9kP!O_
Md {,@ G
k&DHQvfB
public void splitterStop() @WU_GQas3
{ 2ezuP F
bStop = true; $YSD%/c
} );z}T0C
$_Qo
AEnS_Q
} ojVpw4y.
^;s`[f|w
i&>,aiH@
/* 0m`7|80#P
**FileAccess.java z[v5hhI)4
*//文件访问(定位，写) n/?5[O-D]
package NetFox; B;;D(NH
import java.io.*; &J hN&Ur
?GFxJ6!%I
9'toj%XQ
public class FileAccessI implements Serializable{ G>mgoN
MmWJYF=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Pz|qy,
RandomAccessFile oSavedFile; &"tce6&
long nPos; r$v?[x>+K
[k'Ph33c
c(#`z!FB
public FileAccessI() throws IOException <YeF?$S}
{ G<jpJ
this("",0); U-FA^c;
} 6@XutciK
)1fQhdO}x
@L<[38
public FileAccessI(String sName,long nPos) throws IOException DQlaSk4hF_
{ b7AuKY{L
oSavedFile = new RandomAccessFile(sName,"rw"); HnP;1Gi
this.nPos = nPos; oLr"8R\d>t
oSavedFile.seek(nPos); !W%HAlUAG[
} X^|oY]D
zK-hNDFL{
\aZ(@eF@@Q
public synchronized int write(byte[] b,int nStart,int nLen) 0='DDy
{ : l>Ue&
int n = -1; @>9p2u)=
try{ TLSy+x_gX
oSavedFile.write(b,nStart,nLen); B?0{=u
n = nLen; u\e#_*>
} j^%i?BWw
catch(IOException e) btOTDqG`a
{ =H,cwSE+%
e.printStackTrace (); 7t04!dD}
} CMBW]b|
<go~WpA|r
qz0v1057#
return n; 4[J3HLQ
} ,#wVqBEk
3,vH:L4
68HX,t
} {-Y_8@&
kuH;AMdv
g?>AY2f[5
/* /5x`TT
**SiteInfoBean.java T),:8/
*/ ]F@md(J
package NetFox; *(vq-IE\$
\OU+Kl<
YjX=@
public class SiteInfoBean { 42wcpSp
Mb>6.l
5pok%g
private String sSiteURL; //Site's URL *[SsvlFt
private String sFilePath; //Saved File's Path H*\[:tPa
private String sFileName; //Saved File's Name .d"+M{I
private int nSplitter; //Count of Splited Downloading File tH'VV-!MZ
vR)7qX}
6fV)8,F3
public SiteInfoBean() w//w$}v
{//nSplitter的缺省值为5 Y=rr6/k
//default value of nSplitter is 5 b}4/4Z.
this("","","",5); N/%#GfXx
} (t]>=p%4g
qXI30Yo#d
*n*y!z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r\ %O$zu
{ vv0zUvmT
sSiteURL= sURL; t3GK{X
sFilePath = sPath; d_,tXV"z&
sFileName = sName; 4jz]c"p-
this.nSplitter = nSpiltter; yQA[X}
epbp9[`
=a!6EkX *
} u.[JYZ
V1:3
]T51;j'48
public String getSSiteURL() <kSaSW
{ h]Oplp4\W
return sSiteURL; w3w*"M
} # 0!IUSa
"B}08C,?
O0{
public void setSSiteURL(String value) U]D.z}0
{ K%}I}8M
sSiteURL = value; }}1/Ede{5
} =|!~0O
.cF$f4>2
"?{yVu~9
public String getSFilePath() -(uBTO s
{ BLH=:zb5
return sFilePath; :'dc=C
} l1)pr{A
Qyjuzfmz
'U"3'jh
public void setSFilePath(String value) Gx!RaZ1
{ NACY;XQ%
sFilePath = value; k@aP&Z~
} 8@aS9th$
Rdg0WT*;j
O|RO j
public String getSFileName() DjIswI1I
{ #(IMRdUf
return sFileName; ~|9LWp_
} #Q@6:bBzv
XC1lo4|
;0!Wd
public void setSFileName(String value) 9,5II0N L
{ 62x< rph
sFileName = value; &&]!+fTZ\(
} $M`;."
++!E9GU{
'TrrOq4
public int getNSplitter() i`aG
{ YB{E=\~
return nSplitter; mY8=qkZE
} >ij4z N
Cj1UD;
B^(rUR
public void setNSplitter(int nCount) $l;tP
{ DiQkT R
nSplitter = nCount; b<(UmRxx3
} %B&?D@
} I*t)x,~3
_*$B|%k
ba9<(0`
/* '<=MhNh\
**Utility.java gqD^Bs'VF
*/ JGDUCb~
package NetFox; m90R8 V
.XKvk(9
PBs<8xBx^
public class Utility { g**%J Xo
*z"1MU
e6i./bf3
public Utility() y}-S~Ov>I
{ .(1j!B4^
Kc[u} .U
).!14Gjo
} @ KPv&UB
pu$XUt
//线程睡眠 >jz%bY
public static void sleep(int nSecond) [9U srpYi
{ ;9 &1JX
try{ w52HN;Jm
Thread.sleep(nSecond); DYKV54\ue
} eAYW%a
catch(Exception e) ~`>26BWQz
{ )4)iANH?
e.printStackTrace (); `;qv}
} xFm{oJ!]&
} C$RAJ
Omh&)|Iql
//日志 Fl+tbF
public static void log(String sMsg) ]t*P5
{ vx5o k1UY
System.err.println(sMsg); tbzvO<~
} q\b ?o!#_
,o>pmaoLs
ua|Z`qUyq
public static void log(int sMsg) fAM4Q
{ jbhJ;c:
System.err.println(sMsg); 5-5(`OZ{'
} 1xdESorX(
} _IKP{WNB
G2+)R^FSC
D@(M+u9/%
/* ul=a\;3x#|
**TestMethod.java ioY\8i
*/ d!QD vO
package NetFox; 9 QCpXy
zj$_iB`9
=Sb:<q+Q
public class TestMethod { gjegzKU
8 1KG1i)
rI^~9Rz
public TestMethod() p-yOiG8b}
{ ///xx/weblogic60b2_win.exe a,57`Ks+n<
try{ qgC-@I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?` eYWZ">
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &X]=Qpl
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,4>WLJDo
fileFetch.start(); /Xu;/MMpd3
} Z:o 86~su
catch(Exception e){e.printStackTrace ();} Vi?~0.Z%
gLxT6v5wk.
*L4]\wf
} _KM$u>B8
hKH$AEHEU}
Ss<_K>wk
public static void main(String[] args) d1uG[
{ lq\'
new TestMethod(); F'UguC">
} 1Oca@E\Z.
} ^Azt.\fMX
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