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)); Af;Pl|Zh[
} L/"};VI
for(int i=0;i<nEndPos.length-1;i++) /l*v *tl
{ ^HSxE
nEndPos = nStartPos[i+1]; @.e X8~3=
} >ou=}/<
nEndPos[nEndPos.length-1] = nFileLength; < '5~p$
} HY)xT$/J
} <:v+<)K
8%7%[WC#
&:&89<C'
//启动子线程 ?bB>}:~j)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *p}mn#ru-
for(int i=0;i<nStartPos.length;i++) gF{ehU%
{ v|%41xOsr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bmv8nal<Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !%G]~
nStartPos,nEndPos,i); 7Jf~Bn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j,M$l mR')
fileSplitterFetch.start(); *): |WDR
} |h]V9=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fg^25g'_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZRagM'K
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vA/SrX.
nEndPos = " + nFileLength); G)Gp}4gV}
// fileSplitterFetch[nPos.length-1].start(); ,MCTb'=G
+`HMl;0m
E=s,-
//等待子线程结束 o+a=
//int count = 0; ~rb0G*R>
//是否结束while循环 P8d
boolean breakWhile = false; +~^S'6yB
n[3z_QI
,9P-<P
while(!bStop) U**8^:*y#:
{ "6f`hy
write_nPos(); +/ukS6>gr
Utility.sleep(500); M~:_^B
breakWhile = true; +Q5O$8i
*-T.xo
cE]z Tu?!
for(int i=0;i<nStartPos.length;i++) =}`d
{ ic2D$`M
if(!fileSplitterFetch.bDownOver) u&:N`f
{ =l`)b
breakWhile = false; NIV}hf YF
break; Pd91<L
} v"G1vSx)BT
} y]j.PT`Cw
if(breakWhile) 75# 8P?i
break; g&$=Y7G
tIuM9D{P
*2/Jg'de
//count++; axC|,8~tq
//if(count>4) Z=JKBoAY
// siteStop(); 1sqE/-v1_^
} P(D>4/f3"
rnIjpc F
#A/OGi
System.err.println("文件下载结束！"); ")Fd'&58
} ?@b6(f xX
catch(Exception e){e.printStackTrace ();} h*S"]ye5
} -n _Y.~
S<nF>JRJa
rqamBm 5
//获得文件长度 #1<m\z7l
public long getFileSize() ]Ur/DRNS
{ [b++bCH3
int nFileLength = -1; l]]NVBA])
try{ fs!dI
URL url = new URL(siteInfoBean.getSSiteURL()); l~r;Grd/5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C]L)nCOBX
httpConnection.setRequestProperty("User-Agent","NetFox"); hfwJZ\_60
)CFJXc:
f8Hq&_Pn
int responseCode=httpConnection.getResponseCode(); ~apt,hl
if(responseCode>=400) b'z $S+
{ C>Ik ;
processErrorCode(responseCode); 7hk)I`o65
return -2; //-2 represent access is error |bnd92fvks
} ]v ${k
A({czHLhN5
xs"i_se
String sHeader; h"`\'(,X
J6Ilg@}\
'LYDJ~
for(int i=1;;i++) 2/?Zp=|j\
{ C[^VM$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lJK]S=cd
//Utility.log(in.readLine()); tia}&9;
sHeader=httpConnection.getHeaderFieldKey(i); Ic/hVKYG5
if(sHeader!=null) v$}^$8`
{ I-#!mFl
if(sHeader.equals("Content-Length")) u+)!C*ho
{ mY 1l2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TNu%_ 34
break; EavBUX$O
} B7\4^6Tx
} @yTu/U
else ZdW+=;/#
break; /$; Z ~^P
} o-<i+To%
} yhH2b:nY(9
catch(IOException e){e.printStackTrace ();} uX7L1~s-
catch(Exception e){e.printStackTrace ();} FWW4n_74
0)dpU1B#M
(TeH)j!
Utility.log(nFileLength); (PpY*jKR
DI0& _,
aCU[9Xr?
return nFileLength; +Y?Tri
} -h8mJ D%Oi
^*P?gG
eXl?f_9
//保存下载信息（文件指针位置） @fd<
private void write_nPos() e@hPb$7
{ C >OeULD
try{ ]5'*^rz ^
output = new DataOutputStream(new FileOutputStream(tmpFile)); _c]}m3/
output.writeInt(nStartPos.length); Q=Q+*oog
for(int i=0;i<nStartPos.length;i++) d!I%AlV
{ `q}D#0
// output.writeLong(nPos); LW=qX%o{
output.writeLong(fileSplitterFetch.nStartPos); =9&2udV1
output.writeLong(fileSplitterFetch.nEndPos); JQ+Mg&&Q
} 48p3m)5
output.close(); KDN#CU
} V FM[-
catch(IOException e){e.printStackTrace ();} ?c.\\2>|F
catch(Exception e){e.printStackTrace ();} HVM%B{(
} I(6%'s2
cC8$oCR?
|6AR!
//读取保存的下载信息（文件指针位置） Gb^63.}
private void read_nPos() i3 js'?7E
{ ZRhk2DA#FF
try{ )=)N9CRy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &^ERaPynd
int nCount = input.readInt(); B} qRz
nStartPos = new long[nCount]; (CQ! &Z8
nEndPos = new long[nCount]; m]DP{-s4
for(int i=0;i<nStartPos.length;i++) {JWixbA
{ T)tr"<F5NP
nStartPos = input.readLong(); [)`*k#.=
nEndPos = input.readLong(); yK{P%oh)
} RlfI]uCDM
input.close(); {r&r^!K;
} &wNr2PHd#
catch(IOException e){e.printStackTrace ();} cJSNV*<
catch(Exception e){e.printStackTrace ();} W@}@5,}f>
} B+FTkJ0t+G
+aL6$
x.gzsd
private void processErrorCode(int nErrorCode) |mhKD#:
{ oX6Cd:c-
System.err.println("Error Code : " + nErrorCode); >uCO=T,|
} PCCE+wC6
X}B]5
ejg!1*H@n
//停止文件下载 J#d,?
public void siteStop() .UxkTads
{ H8HH) ^
bStop = true; e\z,^
for(int i=0;i<nStartPos.length;i++) 0Y`+L6&UX
fileSplitterFetch.splitterStop(); |f}wOkl
`c:r`Oi?
ZZi9<g1
} 6X ]I`e
} eI|FrBq%
//负责部分文件的抓取 z{.&sr>+v
**FileSplitterFetch.java @kd$.7Y9
*/ s\.r3U&6
package NetFox; 2zo>`;l
c%<81Y=
S*r }oX0
import java.io.*; dhLd2WSyH
import java.net.*; # wn>S<
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b?k,_;\
public class FileSplitterFetch extends Thread { Pw6l'
^cdbM
YloE4PAY7
String sURL; //File URL E=.J*7
long nStartPos; //File Snippet Start Position +)9=bB
long nEndPos; //File Snippet End Position 8hV4l'Pa72
int nThreadID; //Thread's ID ;180ct4
boolean bDownOver = false; //Downing is over =>*}qen
boolean bStop = false; //Stop identical _bh$ t
FileAccessI fileAccessI = null; //File Access interface >>=zkPy
7\dt<VV
VU\G49
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NX8w(~r,:
{ Xe}I;sKrB
this.sURL = sURL; = CXX.%N
this.nStartPos = nStart; gC6Gm':c
this.nEndPos = nEnd; yFo8x[
nThreadID = id; i&HU7mP/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W__$ i<1
} UXa%$gwFw
B_!S\?}$
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public void run() "97sH_ ,
{ f`}u9!jVR
while(nStartPos < nEndPos && !bStop) jp-(n z\
{ 9aID&b+
(>Sy,
T+V:vuK
try{ 5=s|uuw/
URL url = new URL(sURL); K/&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @&h_+|:-
httpConnection.setRequestProperty("User-Agent","NetFox"); Q{hK+z`D
String sProperty = "bytes="+nStartPos+"-"; &Ai+t2
httpConnection.setRequestProperty("RANGE",sProperty); 6_EfOD9
Utility.log(sProperty); jJ>I*'w
H2_6m5[&,
j"0TAYmXwu
InputStream input = httpConnection.getInputStream(); TIV|7nKL
//logResponseHead(httpConnection); N,)rrBD
F0xm%?
"t{D5{q|[k
byte[] b = new byte[1024]; p=Qo92 NH
int nRead; 2$Z4 >!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZB}zT9JaE
{ k%RQf0`T
nStartPos += fileAccessI.write(b,0,nRead); WAr6Dv,8
//if(nThreadID == 1) ohPXwp?]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); voN,u>U
} NS4W!o;"
T.!.3B$@]
:2L-Nf
Utility.log("Thread " + nThreadID + " is over!"); 7r3EMX\#Qm
bDownOver = true; <l)I%1T_c
//nPos = fileAccessI.write (b,0,nRead); En+`ZcA\z
} }g.)%Bw!
catch(Exception e){e.printStackTrace ();} ovtZHq/
} cMUmJH
} Mc|UD*Z
LZPLz@=&]
c5Hm94,p
//打印回应的头信息 e58tf3
public void logResponseHead(HttpURLConnection con) GQkI7C
{ ()$tP3o
for(int i=1;;i++) w3Qil[rg
{ }8'bXG+
String header=con.getHeaderFieldKey(i); i/DUB<>p6
if(header!=null) }5gQ dj[Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); CIt@xi#I
Utility.log(header+" : "+con.getHeaderField(header)); cj3P]2B#
else } AHR7mu=
break; Daf;; w
} LZpqv~av
} u_)'}
k8sjW!2
'k$j^|r>
public void splitterStop() p\|*ff0
{ LwCf}4u"
bStop = true; b;e*`f8T3c
} alQ:'K
(d5kD#.N
fH 5/
} s4\_%je<v
\N]2V(v
Xpf:I
/* X04JQLhy"
**FileAccess.java o7@81QA!e
*//文件访问(定位，写) i\k>2df
package NetFox; )6-!,D0db
import java.io.*; 2HREO@._)
ON3~!Q)
,dk!hm u
public class FileAccessI implements Serializable{ k'{Bhi4
6SD9lgF*-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &Sp2['a!
RandomAccessFile oSavedFile; }W* q
long nPos; lZ}H?n%
B}p{$g!
)1!*N)$
public FileAccessI() throws IOException 1O;q|p'9
{ uyWt{>$
this("",0); G8p6p6*
} f>_' ]eM%
Y]{~ogsn$:
|"EQyV
public FileAccessI(String sName,long nPos) throws IOException xrl!$xE GX
{ b\Gw|?Rv
oSavedFile = new RandomAccessFile(sName,"rw"); DlbNW& V
this.nPos = nPos; w57D qG>
oSavedFile.seek(nPos); L(qQ,1VY
} uY|-: =
=ET|h}I
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public synchronized int write(byte[] b,int nStart,int nLen) !@kwHJkv
{ Tf?|*P
int n = -1; 3N5b3F
try{ qUtlh,4)
oSavedFile.write(b,nStart,nLen); TW}nO|qw
n = nLen; e47N9&4
} 3rw<#t;v
catch(IOException e) :HQQ8uQfb
{ x.~AvJ
e.printStackTrace (); }0~4Z)?e3
} x\R 8W8M
m'.y,@^B
rOd~sa-H
return n; CQm(N
} wLz@u$u?
&C=[D_h
^8eu+E.{
} avo[~ `.
1US4:6xX_
$UGX vCR
/* #Z]l4d3{T
**SiteInfoBean.java Gg=Y}S7:
*/ yJAz#~PO/
package NetFox; /KH,11)yc
kls 6Dk#
U0X?~ 1
public class SiteInfoBean { 9s'[p'[Z
HTU?hbG(
ev;R; 0<
private String sSiteURL; //Site's URL \_J;i[
private String sFilePath; //Saved File's Path a8laPN
private String sFileName; //Saved File's Name 1z$K54Mj
private int nSplitter; //Count of Splited Downloading File P4S]bPIp
Q9h;`G 7t
#?EmC]N7
public SiteInfoBean() 48Z0aA~+
{//nSplitter的缺省值为5 CDU$Gi
//default value of nSplitter is 5 %qqX-SF0C
this("","","",5); .~t.B!rVSB
} {gwJ>]z"e
Xe7/
YA[\|I33
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H!yqIh
{ /f0*NNSat-
sSiteURL= sURL; ~dc~<hK
sFilePath = sPath; DYFfq
sFileName = sName; sV`!4 u7%}
this.nSplitter = nSpiltter; S)$iHBx{
E\Et,l#|LY
(6#, $Ze
} YZyV
-\V!f6Q
,`O.0e4pn
public String getSSiteURL() QpZCU]
{ dF<GuS;l5
return sSiteURL; 6./3w&D;
} +1o4l i
T>2_r6;
`8sC>)lrwu
public void setSSiteURL(String value) ]d]rV `RF
{ 3q*p#l~
sSiteURL = value; Uop`)
} sOUQd-!"
nWz7$O
6z keWR
public String getSFilePath() |`,AAa
{ -.=:@H}r
return sFilePath; E6zSMl5b
} ?6T\uzL +%
M\rZr3
kt;uB X3
public void setSFilePath(String value) }a?(}{z-
{ X&14;lu%p
sFilePath = value; y}bliN7;1e
} O~ ]3.b
y8arFG
y1c2(K>tu
public String getSFileName() +l)[A{
{ -b`O"Ck*
return sFileName; d,d ohi
} zD,K_HicI
o;5ns
#<*=)[
public void setSFileName(String value) 'YTSakNJ}
{ 1@W*fVn
sFileName = value; :qe.*\ c
} ?hh#@61
1@S(v L3a
NwbX]pDT
public int getNSplitter() r&_bk Y%
{ VkJBqRzBOa
return nSplitter; RR9G$}WS(
} UOYhz.
V krjs0
gHmy?+)
public void setNSplitter(int nCount) (29BS(|!
{ 6[~_;0
nSplitter = nCount; d;FOmo4
} { d|lN:B
} W|-<ekH_u
p%ZOLoc)Y
RHv|ijYy
/* DT#F?@LG(
**Utility.java J-d>#'Wb|
*/ *1c1XN<7
package NetFox; e61e|hoX\
'?)<e^
:F`-<x/
public class Utility { &X&msEM
;U<}2M!g
cl1>S3
public Utility() Or<OmxJg
{ $;VY`n
4IGn,D^
/n-!dXi
} o7sIpE9
- xKa-3
//线程睡眠 gPqdl6#c
public static void sleep(int nSecond) =s/UF_JN
{ we}G%09L
try{ NSkIzaNY
Thread.sleep(nSecond); uG,*m'x']
} |kK_B :K
catch(Exception e) 26B+qXEt
{ 94Q?)0W$
e.printStackTrace (); U#>K(
} 'Hv=\p4$1
} teX)!N [
'9XSz?
//日志 D7|qFx;]g
public static void log(String sMsg) 2qpUUo f
{ M T]2n{e
System.err.println(sMsg); 4D=^24f`0
} Aw"Y_S8.
*c>B,
zr@HYl
public static void log(int sMsg) <:ptNGR
{ R?5v//[
System.err.println(sMsg); Cc&SHG*R
} Gc*p%2c
} |{V@t1`
7&w$@zs87
/5N`Euw
/* p,K!'\
**TestMethod.java JDP/vNq
*/ (,^jgv|I
package NetFox; `BzjDI:a
G3${\'<
k@}g?X`8
public class TestMethod { L=9^Y/8Q
&e)V!o@wJV
P&sYS<9q
public TestMethod() B2T=O%
{ ///xx/weblogic60b2_win.exe Aq;WQyZ2
try{ 'y%*W:O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jeWI<ms
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {n 4W3
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^E]y >Y
fileFetch.start(); ;/ASl<t,
} nxhn|v
catch(Exception e){e.printStackTrace ();} ^?R8>97_?
8fWk C<f}
\V%l.P4>e
} m<I>NYfE
"1z#6vw5a
lQKq{WLFx.
public static void main(String[] args) WY$c^av<
{ vocWV/
new TestMethod(); ZVni'ym
} ?5j}&Y3
} QE4TvnhK
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