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)); e"|9%AW@<
} J:mOg95<
for(int i=0;i<nEndPos.length-1;i++) %/MK$
{ 3)g1e=\i$
nEndPos = nStartPos[i+1]; X6<HNLgra
} %3VwCuE
nEndPos[nEndPos.length-1] = nFileLength; [*>@hx
} xt"/e-h}
} ^j=_=Km]
}wkBa]
5>w>J
//启动子线程 _L!"3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D\V}Eo';6
for(int i=0;i<nStartPos.length;i++) 73.o{V
{ >8tE`2[i*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &:jE+l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nw5#/5xw
nStartPos,nEndPos,i); oaBfq8,;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I"JT3[*s
fileSplitterFetch.start(); ESASsRzk
} $@&bK2@.(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,_lwT}*w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @3S2Xb{ra1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "ej>1{3Y:=
nEndPos = " + nFileLength); I( y Wct
// fileSplitterFetch[nPos.length-1].start(); l1wxs@](
Il;'s
sq)Nn&5A
//等待子线程结束 sX_^H%fd
//int count = 0; t8)Fkx#8}
//是否结束while循环 {fN_itn
boolean breakWhile = false; >v<}$v6D~
#t(?8!F
a*IJ)'S
while(!bStop) "a"[B'
{ ld@f:Zali
write_nPos(); 7\/O"Ot
Utility.sleep(500); *,-YWx4
breakWhile = true; P7y[9|^
!s)$_tG
329xo03-[
for(int i=0;i<nStartPos.length;i++) :6M0`V;L
{ [7s5Vt|
if(!fileSplitterFetch.bDownOver) mifYk>J^9
{ .D>lv_kp
breakWhile = false; r2H'r ,N
break; Vi?Z`G]w!
} y=j[v},4
} eO9nn9lql
if(breakWhile) <s7{6n')
break; .$OInh
B6pz1P?e}
Uq+ _#{2(
//count++; P`%ppkzV6
//if(count>4) p4AXQuOP
// siteStop(); ;_SS3q
} :<v$vER,&
!KlSw,&=.6
0$_imjZ
System.err.println("文件下载结束！"); [qI*]
} &+^ # `nq
catch(Exception e){e.printStackTrace ();} f:Ja
} eS=k 48'U
?^!dLW
0l6djN
//获得文件长度 R`?^%1^N
public long getFileSize() SWGa%6|
{ v}Nx*%
int nFileLength = -1; ;' W5|.ZN
try{ mT>p:G
URL url = new URL(siteInfoBean.getSSiteURL()); a?MtY EK2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^MW%&&,BL
httpConnection.setRequestProperty("User-Agent","NetFox"); ri;M7rg`.{
BT1'@qF
-U $pW(~
int responseCode=httpConnection.getResponseCode(); |G@)B!>
if(responseCode>=400) _Kj.
{ IjRmpVcwN
processErrorCode(responseCode); 16Y~5JAc
return -2; //-2 represent access is error q{ 1U
} zLqp@\sT
614/wI8(
Ft rw3OxN
String sHeader; FlG^'UD
2ML6Lkk
)It4al^\
for(int i=1;;i++) sZB6zTX J
{ `6$b1qv,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jq)|7_N
//Utility.log(in.readLine()); Umt ia~x=&
sHeader=httpConnection.getHeaderFieldKey(i); wIj2 IAD
if(sHeader!=null) 7uxPkZbb
{ l,L=VDEz,
if(sHeader.equals("Content-Length")) Av>j+O ;
{ {:X];A$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PcHFj+:
break; Lp)8SmN
} 26VdRy{[
} f4T0Y["QA
else U3K<@r
break; r(T/^<
} "BfmX0&?
} X/Rx]}[
catch(IOException e){e.printStackTrace ();} l_-n&(N2<[
catch(Exception e){e.printStackTrace ();} 'f7 *RSKqb
Pq>[q?>?
xBfe8lor
Utility.log(nFileLength); }a1Sfl@`3
G?d,$NMo|
]U1,NhZu
return nFileLength; cu`J2vm3
} `A _8nW)
Zt2@?w;
GR[>mkW!M
//保存下载信息（文件指针位置） ~yH>Ko9F}
private void write_nPos() ?EQ^n3U$
{ kz;_f
try{ ![]I%'s
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q_0x6]/!
output.writeInt(nStartPos.length); :+Q"MIU
for(int i=0;i<nStartPos.length;i++) <N=p:e,aN,
{ }R&5qpl
// output.writeLong(nPos); d74g|`/
output.writeLong(fileSplitterFetch.nStartPos); &:CjUaP@
output.writeLong(fileSplitterFetch.nEndPos); 71"JL",
} wV[V#KpX8-
output.close(); _RL-6jw#o
} 1uS-Tx
catch(IOException e){e.printStackTrace ();} *Z]WaDw
catch(Exception e){e.printStackTrace ();} )uid!d
} 51M^yG&M
l \^nC2
V}|v!h[O8
//读取保存的下载信息（文件指针位置） ]AA%J@
private void read_nPos() 3[=`uO0\7
{ fEw=I7{Y
try{ ,#bb8+z&p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '#N5i
int nCount = input.readInt(); <@e+-$
nStartPos = new long[nCount]; 6Z7pztk
nEndPos = new long[nCount]; xeHb89GnoQ
for(int i=0;i<nStartPos.length;i++) lgonR
{ N8XC~Dh{
nStartPos = input.readLong(); j:e^7|.
nEndPos = input.readLong(); `N,Vs n"
} 5{FM#@
input.close(); Ybt_?Q9#]
} ?ng14e
catch(IOException e){e.printStackTrace ();} 9vp%6[
catch(Exception e){e.printStackTrace ();} PNJe&q0*
} f>8B'%]
;>Ca(Y2M
/iUUM t'
private void processErrorCode(int nErrorCode) \POnsM)+l
{ \|~?x#aA
System.err.println("Error Code : " + nErrorCode); ^b"bRQqm
} 1O9p YW5J
qqe2,X?
nQ642i%RQ
//停止文件下载 !)%>AH'
public void siteStop() =F'M~3M
{ f#v#)Gp+
bStop = true; 98A(jsj
for(int i=0;i<nStartPos.length;i++) Dr6s^}}~n
fileSplitterFetch.splitterStop(); g8,?S6\nMz
=a9etF%B
M20Bc,VI
} z9M.e.
} i-k >U}[%
//负责部分文件的抓取 t$K@%yU2
**FileSplitterFetch.java If-,c^i
*/ Ns2,hQFc
package NetFox; 3ximNQ}S
9k\)tWe
x7.QL?qR.
import java.io.*; Hwp{<
import java.net.*; JY2/YDJ
}Kj Ju;
n5v'
public class FileSplitterFetch extends Thread { lMC{SfdH
0iJ!K;A2%
_~;&)cn,0
String sURL; //File URL NfTCpA
long nStartPos; //File Snippet Start Position hj&fQ}X
long nEndPos; //File Snippet End Position 5iQmZ[
int nThreadID; //Thread's ID zLsb`)!
boolean bDownOver = false; //Downing is over Ufdl|smt1
boolean bStop = false; //Stop identical X>Al:?`}N
FileAccessI fileAccessI = null; //File Access interface <&5m N
yuHZ&e
2mqK3-c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KdT[*-
{ DH:GI1Yu>I
this.sURL = sURL; GIm " )}W
this.nStartPos = nStart; 1~2R^#rm
this.nEndPos = nEnd; jg [H}
nThreadID = id; sdJ%S*)5G$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 22`oFXb'
} dGW{l]N
OXHvT/L`
C$<"w,
public void run() VEj$^bpp5s
{ uf)W-Er6~
while(nStartPos < nEndPos && !bStop) J7BFk ?=
{ NunV8atn:
:n'yQ#[rn
|h&<_9
try{ "l@A[@R
URL url = new URL(sURL); qoj^_s6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /!3ZWXY\
httpConnection.setRequestProperty("User-Agent","NetFox"); D|d4:;7
String sProperty = "bytes="+nStartPos+"-"; B<|VeU
httpConnection.setRequestProperty("RANGE",sProperty); mC i[Ps
Utility.log(sProperty); .u1X+P7
Y[Q@WdE9
_1^8xFe2
InputStream input = httpConnection.getInputStream(); $. %L
//logResponseHead(httpConnection); LY]nl3{E
^rv"o:lF
z %x7fe
byte[] b = new byte[1024]; &<,SV^wag
int nRead; l~bKBz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Jyj0Gco
{ 6HoqEku/Q
nStartPos += fileAccessI.write(b,0,nRead); [X,A'Q
//if(nThreadID == 1) AR%hf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /+VIw`E
} CjZZm^O
?Z q_9T7
w*50ZS;N
Utility.log("Thread " + nThreadID + " is over!"); AL$W+')
bDownOver = true; bGv*-;*
//nPos = fileAccessI.write (b,0,nRead); L#D9@V'z
} ZJ;LD*
catch(Exception e){e.printStackTrace ();} =/FF1jQ
} gH %y
} w |_GV}#_
o+nG3kRD
xXX/]x>
//打印回应的头信息 A\K,_&x1Z
public void logResponseHead(HttpURLConnection con) )^4hQ3BS
{ `Da+75 f6v
for(int i=1;;i++) ^[k0k(_
{ \PpXL*.
String header=con.getHeaderFieldKey(i); 7K&}C;+
if(header!=null) OL3UgepF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #G_F`&
Utility.log(header+" : "+con.getHeaderField(header)); F|9+ +)
else !z"Nv1!~|
break; ?"6Ov ]
} ) Qq'Wp3i
} W>B^S
Ekv89swl`i
17}$=#SX
public void splitterStop() V/PAi.GZ
{ Py|;kF~![
bStop = true; dpwD8Q< U
} !@G)$g=<
}j46L1T
c<wavvfUo
} -Ep!- a
A\z`c e!
{.st`n|xz
/* u$%A#L[
**FileAccess.java k[\a)WcY8
*//文件访问(定位，写) ["y6b*;x
package NetFox; ju|]Qlek
import java.io.*; c%z'xM
qI%&ay"/
2*[QZ9U[@
public class FileAccessI implements Serializable{ 0,_b)
03=5Nof1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cWMUj K/N
RandomAccessFile oSavedFile; VWx]1\
long nPos; 48O~Jx,
|7"$w%2
2N5`'
public FileAccessI() throws IOException 4zjs!AK%
{ @MiH(.Dq
this("",0); k?*KnfVh!
} {u"8[@@./
$TG=w
j.m(ltGh
public FileAccessI(String sName,long nPos) throws IOException *27*>W1
{ uo2'"@[e
oSavedFile = new RandomAccessFile(sName,"rw"); AiP!hw/V$
this.nPos = nPos; =2Cj,[$
oSavedFile.seek(nPos); *$,:m
} >Lft9e
\]uV!)V5B
Kcy@$uF{2
public synchronized int write(byte[] b,int nStart,int nLen) `JB?c
{ PLX>-7@
int n = -1; %eg+F
try{ jQ\zGJ3
oSavedFile.write(b,nStart,nLen); ]p7jhd=
n = nLen; %<0eA`F4
} e}hmS1>H
catch(IOException e) Jrxz'9qRG
{ oD9^ID+
e.printStackTrace (); =LkR!R=
} l+*&:Q/
@-HG`c ct
n]}W``=7
return n; ?t](a:IX
} Fv74bC%
30>3 !Xqa
Lfog {Vzs
} F@ Swe
c(#;_Ve2P
4_A0rveP
/* A@hppaP!
**SiteInfoBean.java U8.7>ENnP&
*/ _>+8og/%@
package NetFox; R:X0'zeRr
`h:34RC;
":a\z(*t
public class SiteInfoBean { U*3J+Y
YNwp/Y
Fz#X=gmG
private String sSiteURL; //Site's URL bKg8rK u
private String sFilePath; //Saved File's Path 2i;7{7
private String sFileName; //Saved File's Name :cB=SYcC%
private int nSplitter; //Count of Splited Downloading File oVFnlA
;oZ)Wt
R;,g1m|]
public SiteInfoBean() >/[GTqi
{//nSplitter的缺省值为5 ApBWuXp|u
//default value of nSplitter is 5 F8-?dpf'
this("","","",5); -Eu6U`"(
} 2c6g>?
#Cpd9|
@+3kb.P%7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .p0Clr!
{ 1 zw*/dp
sSiteURL= sURL; *(C(tPhC
sFilePath = sPath; HK`I\,K
sFileName = sName; ZKHG!`X0
this.nSplitter = nSpiltter; J'$>Gk]
@)o^uU T
fU=B4V4@
} Mmpfto%i
/xtq_*I1S
I:K"'R^
public String getSSiteURL() PB;eHy
{ 3k#~yaoI
return sSiteURL; ]vwW]O7
} Pj}66.
Cj~'Lhmv'T
}=c85f~i
public void setSSiteURL(String value) AbZKYF P
{ /|* Y2ETOr
sSiteURL = value; .L'.c/ s
} ;>n,:355L
AGLscf.
[w% qV 6
public String getSFilePath() M#(+c_(r
{ *G* k6.9W!
return sFilePath; 8Z(Mvq]f&
} :q#Xq;Wp
:Nofp&
phM>.y_
public void setSFilePath(String value) !pD*p)`s
{ BD(Z5+EU1
sFilePath = value; L4!{h|
} B95B|tU>.
/!c${W!sY
j4qJ.i
public String getSFileName() RzWXKBI\E]
{ 0#nPbe,Lj
return sFileName; YW7b)uYf
} oYukLr
[VE8V-
/`mks1:pK
public void setSFileName(String value) <J^MCqp!v
{ %i5M77#Z
sFileName = value; \otWd
} 4^M
gLOEh6
30SW\@
public int getNSplitter() Ytl4kaYS
{ yU9DSY\m{
return nSplitter; G K7![p
} ?#fu.YE\
E{|W(z,
Y'8?.a]'
public void setNSplitter(int nCount) "1%5,
{ EM[WK+9>I{
nSplitter = nCount; DQr Y*nH
} RJd(~1
} 3.*8)NW
))"6ern
[n:<8ho
/* }hhGu\
**Utility.java !O<)\)|g
*/ "g1)f"pL
package NetFox; k7T`bYv
neLAEHV
oM>Z;QVRC:
public class Utility { G|!on<l&
?.Ca|H<
s+<Yg$)
public Utility() i%0ur}p
{ EwvoQ$#jv
g\&g N
K1M%!JKh)x
} TA4!$7b$
2Eu`u!jhx
//线程睡眠 uC(V
public static void sleep(int nSecond) wY[+ZT
{ NU5.o$
try{ OG>}M$Ora
Thread.sleep(nSecond); ,,q10iF
} toBHkiuD
catch(Exception e) &7K?w~
{ cWe"%I
e.printStackTrace (); KV0]m^@x
} v@ lM3_rbO
} *^VRGfpb
YwjKAyLU
//日志 J^Wa8Q;9lX
public static void log(String sMsg) ^f4s"T
{ hYG6 pTCb
System.err.println(sMsg); kY-N>E:
} Z/Dx,zIR
;'#8tGv=
<^5Z:n!q
public static void log(int sMsg) t*1fLumXR
{ 7`DBS^O]dG
System.err.println(sMsg); $#9;)8J
} %[ Z \S0C
} e?8FN. q
$Avjnm
pL/DZ|S3
/* *V8<:OG|e
**TestMethod.java 7o#I,d~
*/ E/|To
package NetFox; 2y;Skp
N_W}*2(
8c9*\S
public class TestMethod { _x(o*v[Pt
__G?0*3G
&m)6J'q3k
public TestMethod() pZqq]mHK
{ ///xx/weblogic60b2_win.exe R6;=n"Ueb
try{ >4TaP*_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r\'A i6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ) l:[^$=,
SiteFileFetch fileFetch = new SiteFileFetch(bean); iJ1"at
fileFetch.start(); g| I6'K!<
} O;:mCt _H
catch(Exception e){e.printStackTrace ();} (MxQ+D\
MOQ*]fV:
v$?+MNks
} | *2w5iR
"n(hfz0y%
$P/~rZ@M@
public static void main(String[] args) Vc\MV0lr
{ rWa2pO
new TestMethod(); !Qu"BF
} &=] ~0$
} XDOY`N^L
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