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)); wiHGTaR
} >v--R8I*
for(int i=0;i<nEndPos.length-1;i++) M uz+j.0
{ @/jLN
nEndPos = nStartPos[i+1]; j=c=Pe"?u
} 7m='-_w)?w
nEndPos[nEndPos.length-1] = nFileLength; r?Q`b2Q
} xgeDfpF'
} 4u0\|e@a
NEp )V'
z 3((L
//启动子线程 d+DdDr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CWKN0HB
for(int i=0;i<nStartPos.length;i++) Zfwhg4G~
{ vfBIQfH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T .#cd1b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k_d)
nStartPos,nEndPos,i); f0"N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9NzK1V0X
fileSplitterFetch.start(); ;6+e!h'1
} =T7lv%u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P}kBqMM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5@c/,6l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (h&XtFul}
nEndPos = " + nFileLength); #WE"nh9f|z
// fileSplitterFetch[nPos.length-1].start(); <7
ct o+W}k
e8E*Urtz
//等待子线程结束 w2 %u;D%
//int count = 0; fyHFfPEE
//是否结束while循环 '?$N.lj$d
boolean breakWhile = false; /w[B,_ZKTk
o}^/Km+t
@bfW-\ I
while(!bStop) R{6~7<m.
{ Ei$?]~ &
write_nPos(); M( euwy
Utility.sleep(500); 4DLp+6zP
breakWhile = true; 3jeB\
A8|DB@Bi
X1wlOE
for(int i=0;i<nStartPos.length;i++) s<#["K*_
{ Ku'OM6D<
if(!fileSplitterFetch.bDownOver) I| Vyv
{ nf%"7y{dd
breakWhile = false; +F>9hA
break; ^jph"a C
} ioJ~k[T
} %1JN%
if(breakWhile) @'5*u~M
break; gC/~@Z8W]
yW@0Q:
5Yxs_t4
//count++; &PE/\_xD_
//if(count>4) NI<;Lm
// siteStop(); &<Iyb}tA?
} `qXCY^BH2
E\$7tXQK6
ox|K2A
System.err.println("文件下载结束！"); S`w_q=-^8
} n PAl8
catch(Exception e){e.printStackTrace ();} ?@@BIg-
} DA9-F
At t~NTL
QXaE2}}P
//获得文件长度 th :I31
public long getFileSize() n7A %y2
{ {.r jp`39
int nFileLength = -1; [c`u
try{ Gd%X> ~
URL url = new URL(siteInfoBean.getSSiteURL()); B)L=)N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {?+dVLa^;
httpConnection.setRequestProperty("User-Agent","NetFox"); E\_Wpk
Q:v9C ^7
wO-](3A-8P
int responseCode=httpConnection.getResponseCode(); {p90
if(responseCode>=400) 7>@g)%",
{ H Z)an
processErrorCode(responseCode); 9y$"[d27;+
return -2; //-2 represent access is error L!>EW0
} HxE`"/~.7k
RX"~m!26
<w1#3Mu'
String sHeader; TXH9BlDn
g %e"KnU
5eL_iNqJM
for(int i=1;;i++) Qnr7Qnb
{ 1s"/R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R3dt-v
//Utility.log(in.readLine()); Yw!(]8PYdU
sHeader=httpConnection.getHeaderFieldKey(i); >}I BPC
if(sHeader!=null) Ho^rYz
{ Fv!KLw@
if(sHeader.equals("Content-Length")) USDqh437
{ o6b\ w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f3E%0cg
break; >Nho`m(
} f7du1k3
} H)5V \
else MJ%gF=$X
break; {>]7xTpwZ
} Qzh`x-S
} ;ND)h pD+
catch(IOException e){e.printStackTrace ();} 8lJMD %Df:
catch(Exception e){e.printStackTrace ();} )=9EShz!
O_~vl m<#
C)H1<Br7
Utility.log(nFileLength); +\D?H.P
$LXz Q>w9
BIK^<_?+ZU
return nFileLength; ;zpSyyp@
} lk[BS*
iC`mj
s9\HjK*+
//保存下载信息（文件指针位置） jb'AOs
private void write_nPos() No(p:Snbo
{ q33Z.3R
try{ $Y3mO~
output = new DataOutputStream(new FileOutputStream(tmpFile)); +<TnE+>j
output.writeInt(nStartPos.length); cy%S5Rz
for(int i=0;i<nStartPos.length;i++) }b$W+/M\
{ F,)\\$=,
// output.writeLong(nPos); U%qE=u-
output.writeLong(fileSplitterFetch.nStartPos); +jv&V%IL
output.writeLong(fileSplitterFetch.nEndPos); ?z/ )Hkw
} EWZ?q$
output.close(); \|wUxijJ*,
} 2sXNVo8`w"
catch(IOException e){e.printStackTrace ();} >vny9^_
catch(Exception e){e.printStackTrace ();} v "Yo
} id=:J7!QU
$KAOJc4<
0^G5 zQlj
//读取保存的下载信息（文件指针位置） xkPH_+4i8
private void read_nPos() JsY|Fv
{ !o{>[
try{ (;(P3h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g=q1@)
int nCount = input.readInt(); &?wNL@n
nStartPos = new long[nCount]; ] l@Mo7|w
nEndPos = new long[nCount]; 'G|M_ e
for(int i=0;i<nStartPos.length;i++) )^q7s&p/
{ !7fL'
nStartPos = input.readLong(); 1SY`V?cu
nEndPos = input.readLong(); =,HxtPJ
} mDB?;a>
input.close(); :Y\!~J3W
} NW AT"
catch(IOException e){e.printStackTrace ();} L^b /+R#
catch(Exception e){e.printStackTrace ();} R32A2Ml
} KN\*|)
NJqjW
!\(j[d#
private void processErrorCode(int nErrorCode) BK/~2u
{ f?[0I\V[$
System.err.println("Error Code : " + nErrorCode); J6s@}@R1
} ZPO+ #,
wx]r{
[.[|rnil
//停止文件下载 X 8#Uk}/
public void siteStop() f?P>P23
{ 67]kT%0
bStop = true; ;+6TZqklQ
for(int i=0;i<nStartPos.length;i++) ("!P_Q#
fileSplitterFetch.splitterStop(); .9'bi#:Cw
7{fOo%(7
POl_chq
} J}M_Ka
} G-#]|)
//负责部分文件的抓取 A6faRi703
**FileSplitterFetch.java :rcohzfa
*/ W}0cM9 g
package NetFox; ~REP@!\r^
FQp@/H^
7JL*y\'
import java.io.*; D&C83^m
import java.net.*; \:[J-ySJ
^W)h=49PN
"u=U@1 ^
public class FileSplitterFetch extends Thread { qbZY[Q+F
:3h'Hr
]\ DIJ>JZ
String sURL; //File URL M>m+VsJV
long nStartPos; //File Snippet Start Position NBaXfWh
long nEndPos; //File Snippet End Position 7sglqf>
int nThreadID; //Thread's ID {S*:pG:+q
boolean bDownOver = false; //Downing is over X`' @G
boolean bStop = false; //Stop identical C(jUM!m
FileAccessI fileAccessI = null; //File Access interface 7!kbe2/]'
t,4'\nv*
}u9wD08x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'qt+.vd
{ sQ05wAv
this.sURL = sURL; ;mtv
this.nStartPos = nStart; )o\U4t
this.nEndPos = nEnd; ?K>=>bS^h
nThreadID = id; TLWU7aj&!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IJzPWs5W:
} 1O@y >cV
;:l>Kac
1*vt\,G
public void run() wB0Ke
{ 2nsW)bd
while(nStartPos < nEndPos && !bStop) q?TI(J+/
{ %!HBPLk
4Y!_tZ>
66jL2XU<
try{ HgfeSH
URL url = new URL(sURL); xmp^`^v*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E3`&W8
httpConnection.setRequestProperty("User-Agent","NetFox"); `k.Nphx~%
String sProperty = "bytes="+nStartPos+"-"; )(`HEl>-9c
httpConnection.setRequestProperty("RANGE",sProperty); n+qa/<
Utility.log(sProperty); _G1C5nkDl4
?loP18S b
xzrA%1y
InputStream input = httpConnection.getInputStream(); s;NPY
//logResponseHead(httpConnection); XkE'k;AEx
m:4Ec>?e
c*:H6(u
byte[] b = new byte[1024]; $Il:Yw_
int nRead; ek9Y9eJ"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uL1$yf'
{ |o0?u:
nStartPos += fileAccessI.write(b,0,nRead); ,LpGE>s
//if(nThreadID == 1) P S [ifC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1,pg7L8H
} ;VlA~tv
tuWJj^
9X%H$>s
Utility.log("Thread " + nThreadID + " is over!"); pjaDtNb
bDownOver = true; JrhDqyk*
//nPos = fileAccessI.write (b,0,nRead); klON6<w
} {S2? }
catch(Exception e){e.printStackTrace ();} KB6'sj
} o n+:{ad
} u?-X07_
PY{])z3N
/QT"5fxKJ
//打印回应的头信息 8O='Q-&8
public void logResponseHead(HttpURLConnection con) %g+*.8;"b
{ jcVK4jW
for(int i=1;;i++) N sNk
{ v$_YZm{!<
String header=con.getHeaderFieldKey(i); :^H#i:4
if(header!=null) c(5r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RV{'[8gM
Utility.log(header+" : "+con.getHeaderField(header)); n(.U>_ P
else @Fs2J_v
break; U5!T-o;3}
} BL?Bl&p(
} s4uYp
>56I`[)
f 3t&Bcw$
public void splitterStop() c u:1|gt
{ Ed$;#4
bStop = true; y/d/#}\:
} }k7t#O
+;*dFL
,'0Zd(s
} !caY
o1B8_$aYgc
hJsYKd8g
/* vD@=V#T
**FileAccess.java L%sskV(
*//文件访问(定位，写) YKtF)N;m]
package NetFox; F-SD4a
import java.io.*; z&x3":@u<
qo^PS
b!hs|emo;
public class FileAccessI implements Serializable{ {6, l#z
;5TQH_g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m(6SiV=D9
RandomAccessFile oSavedFile; ?9I=XTR
long nPos; c"H59 jE
d} {d5-_a
!da[#zK
public FileAccessI() throws IOException ']]5xH*U
{ sH_5.+,`
this("",0); G+dQ" cI9
} |MEu"pY)
g E#43
Sh(Ws2b7
public FileAccessI(String sName,long nPos) throws IOException 'L1=:g.\i
{ P g{/tMY
oSavedFile = new RandomAccessFile(sName,"rw"); A.@/~\
this.nPos = nPos; yR|Beno
oSavedFile.seek(nPos); Mb0l*'ZF
} YrRD3P.P
7F!(60xY
l]wjH5mz=i
public synchronized int write(byte[] b,int nStart,int nLen) 2qQG
{ n9p_D
int n = -1; W7 iml|WV0
try{ +q NX/F
oSavedFile.write(b,nStart,nLen); BXx0Z %e.3
n = nLen; t!S ja
} 9+!1jTGSkf
catch(IOException e) w,/&oe5M+
{ E` O@UW@
e.printStackTrace (); C % d
} d \[cFe1d
/j|Rz5@=
F[HMX4
return n; yCt,-mz!z
} RD1N@sHDKc
#;*0 Pwe`
qC;1ND
} ]u\K}n6[q
GI ~<clhf
yi-S^
/* FR%u1fi
**SiteInfoBean.java PRo;NE
*/ Uw:gJ9
package NetFox; SmR"gu
Y%"6
nS`DI92I
public class SiteInfoBean { N=hhuKt]
n@ rphJb
oI/jGyY;
private String sSiteURL; //Site's URL LEJ8 .z6$
private String sFilePath; //Saved File's Path 9"%ot=)
private String sFileName; //Saved File's Name [ S_8;j
private int nSplitter; //Count of Splited Downloading File T+9#&
b7nER]R
&Fxw19[G
public SiteInfoBean() 'c")]{
{//nSplitter的缺省值为5 :% o32
//default value of nSplitter is 5 `_*NFv1_
this("","","",5); K@DK4{
} (sHvoE^q-
3$E\B=7/U
luYa+E0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LBs:O*;
{ afJ`1l
sSiteURL= sURL; rElbzL"&<
sFilePath = sPath; icnc5G
sFileName = sName; NDt +m
this.nSplitter = nSpiltter; NE'4atQ|
B"9/+Yj
Xgs 31#K
} K.{:H4_
Z\@m_/g
4Em$L]7
public String getSSiteURL() +d=cI
{ |i-d#x8
return sSiteURL; '&<T;V%
} ?cF-w!>o8
|x[zzx# >-
5m e|dvk
public void setSSiteURL(String value) Ba]J3Yp,z
{ uBPxMwohR
sSiteURL = value; l-GQ AI8
} @aX$}
@&7|Laa
U<|h4'(@L
public String getSFilePath() P<1ZpL
{ }/{G
return sFilePath; BRu/pyxG
} w N-np3k
[`u3SN/P
^{vf|zZ _
public void setSFilePath(String value) GG KD8'j]
{ pjh o#yP
sFilePath = value; Tn'_{@E;
} Gxj3/&]^Y
13X0LN
3Xun>ZQ-
public String getSFileName() IQz:DJ
{ +/L "A
return sFileName; qq)Dh'5*e,
} x-Cy,d:YX
l_Ffbs_6t
qBkI9H
public void setSFileName(String value) tmCm54
{ |6mDooTy
sFileName = value; :YAxL J
} KG5h$eM'
=h#3D?b0n
m^O9G?
public int getNSplitter() WrS|$: 0
{ }.uB6&!:
return nSplitter; U!0 Qf7D
} JMnk~8O
%Q0J$eC
Bx>)i8P7i0
public void setNSplitter(int nCount) yLo{^4a.
{ ##6_kcL:6G
nSplitter = nCount; R-8/BTls7
} \U1fUrw$*
} s /?&H-
cP4K9:k
k>N >_{\
/* PhS`,I^Z
**Utility.java NVTNjDF%s
*/ cvf@B_iN9
package NetFox; YRkp(}*!\
#..-!>lY
]T3dZ`-(
public class Utility { ZW]Q|vPh4U
sw(dd01a 7
OYWW<N+R2
public Utility() _Gpq=(q)
{ $7#N@7
Bhy:" r%#
$9}z^sGIM
} P&ig.Og*
78s:~|WB<{
//线程睡眠 d" "GG/
public static void sleep(int nSecond) IQZBH2R
{ ]aqHk
try{ ;FO1b*
Thread.sleep(nSecond); k{fCU%
} z)Y<@2V*C
catch(Exception e) &IQp&
{ $uA?c& e
e.printStackTrace (); )-_NtMr~`!
} sGf\!w
} iaqhP7!
\LFRu
//日志 FN#6pM']|
public static void log(String sMsg) T:$zNX<f
{ *3yeMxa
System.err.println(sMsg); Yfk){1
} 5$r`e+Nf'
I[~EQ{Iz
6AZJ,Q\E@
public static void log(int sMsg) ]7QRelMiz+
{ B%v2)+?@
System.err.println(sMsg); X(-e-:B4;
} Y* #'Gh,
} kAbkhZ1^
z2m%L0
1_Um6vS#
/* TJ:B_F*bSk
**TestMethod.java OHqc,@a;+
*/ $J/Z~(=JT
package NetFox; $c-h'o
dbkkx1{>Y
Q0K4_iN)&
public class TestMethod { 00') Ol&
)`RF2Y-A7
`"0#lZ`n
public TestMethod() C+r<DC3
{ ///xx/weblogic60b2_win.exe Y",Fs(
try{ z$3 3NM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kilq Jg1%C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lm kv.XF
SiteFileFetch fileFetch = new SiteFileFetch(bean); RVFQ!0 C
fileFetch.start(); `laaT5G\y
} <a-I-~
catch(Exception e){e.printStackTrace ();} or_x0Q
XE_|H1&j
tHSe>*eC
} {x $H#<Y
^X6fgsjz
tJ>OZ
public static void main(String[] args) DWB.dP *8
{ G<kslTPyq
new TestMethod(); r5b5`f4
} JM5w`=
} i|X ;n
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