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)); 91[(K'=&
} UKn>.,
for(int i=0;i<nEndPos.length-1;i++) @_0XK)pW
{ (i&:=Bfn)
nEndPos = nStartPos[i+1]; Lw2EA 5
} "y#$| TMB
nEndPos[nEndPos.length-1] = nFileLength; l8jm7@.E
} JrS|Ib)6
} _sx]`3/86
$Z$BF
Br;1kQ%eC
//启动子线程 yA=#Ji
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rr9N(AoxW
for(int i=0;i<nStartPos.length;i++) KN_3]-+B
{ U H `=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }zj_Pp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w8$8P
nStartPos,nEndPos,i); qK,rT*5=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Me2%X>;
fileSplitterFetch.start(); ?>DN7je
} {0QNqjue
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mM!Gomp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4Bs '5@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kpLDK81I
nEndPos = " + nFileLength); tVFl`Xr
// fileSplitterFetch[nPos.length-1].start(); lfK sqe"
oyK'h9Wt1
<U$x')W
//等待子线程结束 <Y9e n!3\
//int count = 0; GK~uoz:^O
//是否结束while循环 "V}WV!w
boolean breakWhile = false; |!,;IoZ
&r doMc;
X8"4)IZ3
while(!bStop) Z`T]jm-3
{ 2old})CLJ
write_nPos(); ^e1@o\]
Utility.sleep(500); /&_$+Iun
breakWhile = true; cY0NQKUk~
VMXccT9i!
b<n*wH
for(int i=0;i<nStartPos.length;i++) kq8.SvIb
{ gwm!Pw j
if(!fileSplitterFetch.bDownOver) @j=:V!g2O
{ T]HeS(
breakWhile = false; ))66_bech
break; kc-=5l
} ,K 8R%B
} h'jc4mu0
if(breakWhile) "m4._4U
break; <Z5-?wgf9
j4k\5~yzS
gF#HNv
//count++; Py y!B
//if(count>4) 3K!(/,`
// siteStop(); S6Y2(qdP
} T\?$7$/V
.o8Sy2PaV
?I{L^j^#4
System.err.println("文件下载结束！"); 9sG]Q[:.]
} xy))}c%
catch(Exception e){e.printStackTrace ();} >J*x` a3Q
} ct`j7[
rP|~d}+I
#9zpJ\E
//获得文件长度 y)vK=,"
public long getFileSize() /#jH#f[
{ 6I2`oag
int nFileLength = -1; eu={6/O
try{ `Y O(C<r-
URL url = new URL(siteInfoBean.getSSiteURL()); Pm&hv*D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :e1kpQ
httpConnection.setRequestProperty("User-Agent","NetFox"); V^Y'!w\LGI
2[j(C
UE8j8U'L
int responseCode=httpConnection.getResponseCode(); @GUlw[vi
if(responseCode>=400) ZP{<f~;
{ +`,;tz=?
processErrorCode(responseCode); `>)[UG!:|
return -2; //-2 represent access is error 2Pow-o*r
} )G#mC0?PV
/|q.q
ysapvQN_6
String sHeader; VWq]w5oQO
'_d4[Olu
5EU~T.4C<
for(int i=1;;i++) 7UIf
{ {Y-~7@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0FSNIPx
//Utility.log(in.readLine()); "i#aII+T
sHeader=httpConnection.getHeaderFieldKey(i); % IHIXncv[
if(sHeader!=null) "!+gA&
{ {ETM >
if(sHeader.equals("Content-Length")) Z_Wzm!:
{ J3`0i@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }@eIO|
break; Hz\@#
} m/z,MT74*J
} w 5 yOSz
else u 3^pQ6Q
break; b9-IrR4h
} nr2 Q[9~
} _Jy7` 4B.
catch(IOException e){e.printStackTrace ();} F~q(@.b
catch(Exception e){e.printStackTrace ();} 1U% /~
{{jV!8wK
^M{,{bG
Utility.log(nFileLength); JIhEkY
AbxhNNK
z',Fa4@z
return nFileLength; DQT'OZ:w
} [\AOr`7
0j_kK
c/Xg ARCO
//保存下载信息（文件指针位置） rtS' 90`
private void write_nPos() l+[:Cni
{ R&9FdM3K`:
try{ lD[37U!
output = new DataOutputStream(new FileOutputStream(tmpFile)); Fvf|m7
output.writeInt(nStartPos.length); ~:{05W
for(int i=0;i<nStartPos.length;i++) M@#T`aS
{ 9.8%Iw
// output.writeLong(nPos); vfc:ok1
output.writeLong(fileSplitterFetch.nStartPos); s3HVX'
output.writeLong(fileSplitterFetch.nEndPos); -8xf}v~u
} Wl |5EY
output.close(); As<B8e]
} +x(#e'6p
catch(IOException e){e.printStackTrace ();} R*:>h8
catch(Exception e){e.printStackTrace ();} [% C,&h5
} s bj/d~$N
H T|DT
Keozn*fzI
//读取保存的下载信息（文件指针位置） 'C/yQvJ
private void read_nPos() ;xZjt4M1
{ @(Y!$><Is
try{ 6$6QAW0+f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;eN ^'/4A
int nCount = input.readInt(); &W,jR|B
nStartPos = new long[nCount]; yEq7ueJ'
nEndPos = new long[nCount]; TG%B:^Yz!
for(int i=0;i<nStartPos.length;i++) ;%9]G|*{
{ T1]?E]m{
nStartPos = input.readLong(); 7Ml4u%?
nEndPos = input.readLong(); h:nybLw?
} fC[za,PXaE
input.close(); EHk\Q\
} Gq^vto
catch(IOException e){e.printStackTrace ();} H_X^)\oJ
catch(Exception e){e.printStackTrace ();} B1V{3
} ovdJ[bO
hbJ>GSoZ,
z5kAf~A
private void processErrorCode(int nErrorCode) }5-w,m{8/
{ nN\H'{Wzd
System.err.println("Error Code : " + nErrorCode); 9@lWI
} KNUK]i&L
m[^lu1\wn
;f=m+QXU
//停止文件下载 <eoie6@3
public void siteStop() |^6{3a
{ dE7S[O
bStop = true; ^U}k
for(int i=0;i<nStartPos.length;i++) x@t?7 o\&
fileSplitterFetch.splitterStop(); z3Q&O$5\
.\n` 4A1z
+n)n6}S
} "2l`XH
} @1MnJP
//负责部分文件的抓取 )S caT1I
**FileSplitterFetch.java p+;& Gg54
*/ %{@Q7
package NetFox; FQ]/c#J
zaqX};b
fSkDD>&
import java.io.*; >?, Zn
import java.net.*; ;]u9o}[ 2
wI$a1H
{FNkPX
public class FileSplitterFetch extends Thread { ?, S/>SP
DN*5q9.
=~B"8@B
String sURL; //File URL CMXF[X)%
long nStartPos; //File Snippet Start Position AcC &Q:g
long nEndPos; //File Snippet End Position aQCu3T
int nThreadID; //Thread's ID ieFl4hh[G
boolean bDownOver = false; //Downing is over o4);5~1l
boolean bStop = false; //Stop identical .T| }rB<c
FileAccessI fileAccessI = null; //File Access interface 0zaK&]oY0
A&Y5z[p
;mkkaW,D*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iwotEl0*{
{ ,`@pi@<"#
this.sURL = sURL; 7?$?Yu
this.nStartPos = nStart; R4m{D
this.nEndPos = nEnd; 5*AXL.2ih
nThreadID = id; Zt`Tg7m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i[v4[C=WB!
} hF%M!otcJ-
qt@L&v}~j
KK){/I=z
public void run() Fx9-A8oIR
{ E/P~HE{
while(nStartPos < nEndPos && !bStop) O>~,RI!
{ <+`%=r)4
WsI`!ez;D
!@xO]Jwv
try{ Vy\Vpp
URL url = new URL(sURL); >|$]=e,Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l<6u@,%s
httpConnection.setRequestProperty("User-Agent","NetFox"); @(3F4Z.i%.
String sProperty = "bytes="+nStartPos+"-"; >f(?Mxh2
httpConnection.setRequestProperty("RANGE",sProperty); `o[l%I\Q
Utility.log(sProperty); Dac)`/
{.p.?
/jY u-H+C
InputStream input = httpConnection.getInputStream(); Yj%]|E-
//logResponseHead(httpConnection); a.Ho>(V/4
^*K=wE}AG
r|Ui1f5
byte[] b = new byte[1024]; :xd;=;q5
int nRead; . %RM8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b)LT[>f
{ f7Gn$E|/r;
nStartPos += fileAccessI.write(b,0,nRead); d1b]+AG4
//if(nThreadID == 1) L, JQ\!c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); is'V%q
} YuXJT*
T(b9b,ov)
4&/CES
Utility.log("Thread " + nThreadID + " is over!"); JU 9GJ"
bDownOver = true; 22gh!F%)
//nPos = fileAccessI.write (b,0,nRead); j[>cv;h ;
} {/'T:n#
catch(Exception e){e.printStackTrace ();} y0zMK4b
} +P/kfY"
} W(,j2pU
3/G^V'Yu
}>A q<1%
//打印回应的头信息 ]<;,HGO
public void logResponseHead(HttpURLConnection con) Sc)^k
{ _?{7%(C
for(int i=1;;i++) JJ?{V:
{ Ei;tfB
String header=con.getHeaderFieldKey(i); Z_d"<k}I
if(header!=null) "yWw3(V2>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PRKZg]?
Utility.log(header+" : "+con.getHeaderField(header)); o/5-T4
else ARk(\,h
break; ']_2@<XW)
} rQ;w{8J\t
} 5/meH[R\M
HA6tGZP*L
i"8mrWb
public void splitterStop() [>=!$>>;8
{ rP@#_(22
bStop = true; -dntV=
} O9=/\Kc
~+q1g[6
2MkrVQQ9g
} l$42MRi/
|VfEp
'h>uR|
/* |V9[aa*c
**FileAccess.java d*(aue=
*//文件访问(定位，写) $TQhr#C]
package NetFox; &!!*xv-z
import java.io.*; 5>k:PKHL
@u~S!(7.Wi
&Y@i:O
public class FileAccessI implements Serializable{ }X(&QZ7i`
+mQ5\14#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \2SbW7"/;P
RandomAccessFile oSavedFile; m'4f'tbN
long nPos; rzjVUPdnh
c_lHj#A(l
)>volP
public FileAccessI() throws IOException lj4Fg*/Yn
{ Zt=|q$"
this("",0); Q&9yrx.
} P7x;G5'.
S-Uod y
@"@a70WHk
public FileAccessI(String sName,long nPos) throws IOException .3!Wr*o
{ IqOg{#sm
oSavedFile = new RandomAccessFile(sName,"rw"); .sMs_ 5D
this.nPos = nPos; s**<=M GK
oSavedFile.seek(nPos); 36d nS>4
} j\>LJai"
.l}Ap7@
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public synchronized int write(byte[] b,int nStart,int nLen) _|k$[^ln^
{ ZsmOn#`=^}
int n = -1; 2RiJm"
try{ 7Ai?}%b-
oSavedFile.write(b,nStart,nLen); \kADh?phV
n = nLen; sNf& "C!;
} fXD+
catch(IOException e) KA3U W
{ d} >Po%r:
e.printStackTrace (); bIQ,=EA1
} x4_IUIgh
qJey&_
}@DCcf$<
return n; )SV.|
} j=\h|^gA
WI8}_){ d
9zaNfs
} [Nyt0l "z
$d?+\r:I{,
6].[z+
/* MP]<m7669*
**SiteInfoBean.java =BJLj0=N
*/ %sa?/pjK
package NetFox; `Sod]bO +U
4u{S?Ryy
j,IRUx13f
public class SiteInfoBean { W!Tx%
m/HT3<F
N?GTfN
private String sSiteURL; //Site's URL 1wSAwpz
private String sFilePath; //Saved File's Path \Z{tC$|H
private String sFileName; //Saved File's Name uvys>]+
private int nSplitter; //Count of Splited Downloading File iP:i6U]
|vI*S5kn6A
QM$UxWo-
public SiteInfoBean() ZOK!SBn^?
{//nSplitter的缺省值为5 PyeNu3Il4
//default value of nSplitter is 5 6[bopin
this("","","",5); D9rQ%|}S
} 6BE,L
ep>!jMhJa
kpOdyn(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _]:b@gXUw
{ *k?:k78L
sSiteURL= sURL; E)b$;'
sFilePath = sPath; R2bqhSlF
sFileName = sName; bM W|:rn
this.nSplitter = nSpiltter; F.s$Y+c!6
2.qPMqH
}\_.Mg^y
} yOM/UdWq
[8V;Q
~ |G&cg
public String getSSiteURL() _H]\
{ 'nmGHorp
return sSiteURL; 4.A^5J'W
} q^X7x_
w,|@e_|J
unDW2#GX
public void setSSiteURL(String value) 3:nhZN/95T
{ 0KA*6]h t
sSiteURL = value; SmXJQ@jN
} 7?lz$.*Avp
Bk8}K=%w
<JPN< Kv
public String getSFilePath() cXweg;
{ ,05PYBc3
return sFilePath; y<`5
} 7lC$UQx8
!z?
MGdzrcF
public void setSFilePath(String value) "M%R{pGA7
{ D?Oe";"/
sFilePath = value; ]4~Yi1]
} +IZ=E >a
VZ]iep
"&(/bdah?&
public String getSFileName() H4M=&"ll}
{ Ae5A@4
return sFileName; 4KPnV+h"b
} O>`k@X@9/
kUBE+a6#
?<Qbp;WBo
public void setSFileName(String value) q` S ~w
{ Y:*% [\R
sFileName = value; vG|!d+
} z']6C9m}
xj5TnE9^
KGt:
public int getNSplitter() KpN]9d
{ XG#?fr}L
return nSplitter; +'F;\E
} y_PA9#v7
#N{]
A%w9Da?B
public void setNSplitter(int nCount) !Uiq3s`1T
{ _z p<en[
nSplitter = nCount; =7!s8D,[
} rfV'EjiM}
} (Ypy}
Y7GsL7I
py6<QoGV
/* a)|y0w)vV
**Utility.java L: $ `8
*/ a\sK{`|X*
package NetFox; DJGafX^
9.)z]Gav
zC50 @S3|
public class Utility { ?NE/}?a
kBP?_ O
i)l0[FNI}
public Utility() iXWzIb}CJ-
{ Om.%K>V
/gAT@Vx
SIK:0>yK"
} l|q-kRRjn
AA\)BNM
//线程睡眠 t 7Y*/v&P(
public static void sleep(int nSecond) @9^OHRZX
{ w4fKh
try{ j"Jf|Hq $
Thread.sleep(nSecond); |E~c#lV
} |q3X#s72
catch(Exception e) [kg^S`gc#
{ qV=:2m10x
e.printStackTrace (); ):N#X<b':
} Jp jHbG
} L|1,/h 8p
,#;hI{E
//日志 MkW=sD_
public static void log(String sMsg) V7,dx@J-
{ cvcZ\y
System.err.println(sMsg); &mX_\w/%
} 8K4^05*S
*+v*VH
I<}% L V
public static void log(int sMsg) /? %V% n
{ I`{3I-E
System.err.println(sMsg); xLed];2G
} yPE3Awh5
} U\%r33L )
RUY7Y?
O=__w *<
/* ")KqPD6k
**TestMethod.java ,X!)zAmm
*/ aiPm.h>
package NetFox; B}[CU='P*
=!-}q
L9jT:2F
public class TestMethod { ]9_gbQ
eipg,EI
+-tFgXG
public TestMethod() pW+uVv,
{ ///xx/weblogic60b2_win.exe ]x)!Kd2>
try{ rC@VMe|0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pZ8J\4+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -sJ1q^;f@
SiteFileFetch fileFetch = new SiteFileFetch(bean); !aSj1 2J
fileFetch.start(); Oj-\
} 9(t(sP_
catch(Exception e){e.printStackTrace ();} ;6@sC[
HGAi2+&
s(py7{ ^K
} 'goKYl#1Q
*=i&n>
<ll?rPio"
public static void main(String[] args) Muwlehuq
{ Cu`
new TestMethod(); ![Qi+xyc
} xHt7/8wF
} 4Q!A w
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