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)); . zvF!!z
} o;mXk2
for(int i=0;i<nEndPos.length-1;i++) zr?%k]A%UO
{ OC9_EP\"
nEndPos = nStartPos[i+1]; _d&zHlc_
} PIn'tV
nEndPos[nEndPos.length-1] = nFileLength; nbMnqkNb
} '5KgRK"
} 5.#r\' Z#
B=#rp*vwL
<0vQHND,3
//启动子线程 zTBr<:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q(e&{pbM)
for(int i=0;i<nStartPos.length;i++) ;RW!l pGjP
{ ~Rk%M$E9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m,$oV?y>j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QP)-O*+AA
nStartPos,nEndPos,i); xA#B1qbw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #Oz<<G<
fileSplitterFetch.start(); dl@
} {*As-Y:'F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1?`,h6d*=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =;0#F&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RS#)uC5/%
nEndPos = " + nFileLength); mKtZ@r)u
// fileSplitterFetch[nPos.length-1].start(); =-~82%
K_oBSa`
Xdsd5 UUM
//等待子线程结束 R:x4j#(
//int count = 0; %F9%t
//是否结束while循环 "wmQ,=
boolean breakWhile = false; }XWic88!~
.JZoZ.FAb
.B{3=z^
while(!bStop) 'N)&;ADx-G
{ kYl$V=
write_nPos(); ++F #Z(p
Utility.sleep(500); R{\vOw:*
breakWhile = true; :Sk0?WU
U_m<W$"HF
!m^;Apuy
for(int i=0;i<nStartPos.length;i++) 1]aM)},
{ mQtGE[
if(!fileSplitterFetch.bDownOver) }k.-xaj
{ LpeQx\
breakWhile = false; l|^p;z:d
break; 9XX&~GW/
} BJ<hP9#
} ,h5\vWZ
if(breakWhile) o*eU0
break; }H!c9Y
4K[E3aA
a[]=*(AZI
//count++; <s2IC_f<+
//if(count>4) m,,-rC
// siteStop(); v#@"Evh7
} T|Sz~nO}f
X,:^})]
]C3{ _?=
System.err.println("文件下载结束！"); ]Vo;ZY_\
} OGh9^,v
catch(Exception e){e.printStackTrace ();} 3haYb`
} z4b2t}
<w` R;
21bvSK
//获得文件长度 b4ZZyw
public long getFileSize() R22YKXU
{ 0z #'=XWk
int nFileLength = -1; t*m04* }
try{ ?>cx;"xF
URL url = new URL(siteInfoBean.getSSiteURL()); vP`Sz}FU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g&!UaJ[#9
httpConnection.setRequestProperty("User-Agent","NetFox"); zUXQl{
^90';ACFy
u)Y~+ [Q
int responseCode=httpConnection.getResponseCode(); #3>o^cN~8k
if(responseCode>=400) fz\C$[+u
{ f_Ma~'3
processErrorCode(responseCode); K'%2'd
return -2; //-2 represent access is error h:-ZXIv?
} a\>+!Vq
y$|%K3
C-E~z{
String sHeader; $nF|n+m
!TvNT}4Z
g5M=$y/H
for(int i=1;;i++) z/!LC;(
{ ^\ A[^' 9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :+NZW9_
//Utility.log(in.readLine()); 3.@"GS#"[
sHeader=httpConnection.getHeaderFieldKey(i); rV84?75(Y
if(sHeader!=null) a?jUm.
{ .DsdQ4Y
if(sHeader.equals("Content-Length")) uzg(C#sp
{ \ne1Xu:hM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s|F}Abx,^
break; ?lq
} 3}aKok"k
} 2(LF @xb
else WoM;)Q
break; EyR~VKbJ'
} Ln:6@Ok)5%
} cq]JD6937
catch(IOException e){e.printStackTrace ();} Y`F)UwKK
catch(Exception e){e.printStackTrace ();} [wU e"{
V=^B7a.;>
G0#<SJ,)
Utility.log(nFileLength); OT0%p)
YP E1s
.3 >"qv
return nFileLength; $7h]A$$Fv
} -t]3 gCLb
&~mJ ).*
&Va="HNKt
//保存下载信息（文件指针位置） :eIi^K z[
private void write_nPos() Fn>KdoByN
{ ]K?;XA3dZ
try{ Pi+pQFz5
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y5c,O>T5Y
output.writeInt(nStartPos.length); CvhVV"n
for(int i=0;i<nStartPos.length;i++) QPX&P{!g
{ {W+IUvn
// output.writeLong(nPos); ZnKjU ]m
output.writeLong(fileSplitterFetch.nStartPos); p{ Xde
output.writeLong(fileSplitterFetch.nEndPos); dx@|M{jz'
} {FQ@eeU
output.close(); {N3&JL5\"E
} JDJ"D\85
catch(IOException e){e.printStackTrace ();} 3daI_Nx>
catch(Exception e){e.printStackTrace ();} arIEd VfNa
} 1=Z!ZY}}e
7s0\`eXo/
y'aK92pF:
//读取保存的下载信息（文件指针位置） Brtsig,4
private void read_nPos() "(r%`.l=I
{ ;6eBfMhL
try{ fB80&G9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6ao~f?JZ
int nCount = input.readInt(); aFaioE#h(
nStartPos = new long[nCount]; ]A;.}1'
nEndPos = new long[nCount]; yky%+@2q
for(int i=0;i<nStartPos.length;i++) lD^c_b
{ -MRX@a^1
nStartPos = input.readLong(); 5JHWt<n{P
nEndPos = input.readLong(); V/3@iOwD
} h;@c%Vm
input.close(); qnCjNN
} Fw\g\
catch(IOException e){e.printStackTrace ();} \TZSn1isZX
catch(Exception e){e.printStackTrace ();} e)= "Fq!
} !&xci})7a
qJ sH
U9ZuD40\
private void processErrorCode(int nErrorCode) It7R}0Smg
{ tr5j<O
System.err.println("Error Code : " + nErrorCode); SRtw
} Jz}`-fU`
uNkJe
c]h@<wnv
//停止文件下载 0SfW:3
public void siteStop() nY7gST
{ &wAVO_s
bStop = true; Kt](|
for(int i=0;i<nStartPos.length;i++) d~AL4~}
fileSplitterFetch.splitterStop(); ^U5Qb"hz
l\F71pwSI
Nm !~h|3
} [YP{%1*RM
} [GPCd@
//负责部分文件的抓取 NVghkd
**FileSplitterFetch.java CY*o"@-o5)
*/ -)Bvx>8fq-
package NetFox; iO&*WIbg
#i.,+Q
,PmUl=
import java.io.*; Nc&J%a
import java.net.*; (H5#r2h%Y
,{mv6?_
ufCpX>lNF
public class FileSplitterFetch extends Thread { q}+zNeC
_1Q6FI5iR
=&6sU{j*
String sURL; //File URL /o%VjP"<
long nStartPos; //File Snippet Start Position obE8iG@H
long nEndPos; //File Snippet End Position }zks@7kf
int nThreadID; //Thread's ID @R}3f6@67
boolean bDownOver = false; //Downing is over |_+#&x
boolean bStop = false; //Stop identical <#J5.I 1
FileAccessI fileAccessI = null; //File Access interface OLPY<ax
$[}EV(#y
PW|=IPS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k_{?{:X;y
{ Fsm6gE`|n
this.sURL = sURL; Q^ZM|(s#
this.nStartPos = nStart; ]Zt]wnL+
this.nEndPos = nEnd; F)KR8(
nThreadID = id; I 1n,c d[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (BFwE@1"
} ^D5Jqh)
V*ao@;sD
76"4Q!
public void run() DI8<0.L
{ `3i<jZMG
while(nStartPos < nEndPos && !bStop) e@qH!.g)
{ 2,dWD<h
p J_+n:_{
E_En"r)y
try{ $,2T~1tE
URL url = new URL(sURL); PcEE`.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yb-{+H8{J
httpConnection.setRequestProperty("User-Agent","NetFox"); zPND$3&'
String sProperty = "bytes="+nStartPos+"-"; SOq:!Qt
httpConnection.setRequestProperty("RANGE",sProperty); b~}$Ch3ymW
Utility.log(sProperty); |4g0@}nr+W
$:%E<j4Dn
}04mJY[
InputStream input = httpConnection.getInputStream(); JLnv O
//logResponseHead(httpConnection); w8>h6x"
,5"(m?[m
aUzCKX%>C
byte[] b = new byte[1024]; oWL_Hh%-f`
int nRead; u1L^INo/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H)i|?3Ip
{ "5Y6.$Cuf!
nStartPos += fileAccessI.write(b,0,nRead); iX6>u4~(
//if(nThreadID == 1) Vn4wk>b}$2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =V]0G,,\
} 7dcR@v`c
>> "gb/x,
\?>M?6D
Utility.log("Thread " + nThreadID + " is over!"); +:uz=~mo`
bDownOver = true; 'Zp{
//nPos = fileAccessI.write (b,0,nRead); i? ~-%
} n'v\2(&uYN
catch(Exception e){e.printStackTrace ();} /$CTz xd1
} ?/"|tuQMW
} cd1G.10
R8k4?_W?T
R__:~uv,
//打印回应的头信息 _0v+'&bz
public void logResponseHead(HttpURLConnection con) sde>LZet/
{ }VZExqm)
for(int i=1;;i++) itP`{[
{ <M@-|K"Eb
String header=con.getHeaderFieldKey(i); ey=KAt
if(header!=null) N"G aQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q50F!yHC-
Utility.log(header+" : "+con.getHeaderField(header)); 2^=.j2
else z'"7zLQ
break; qEr?4h
} \O;2^
} `,-mXxTNT
=&}_bd/]
/j$=?Rp
public void splitterStop() D<;~eZ'
{ <;S$4tux
bStop = true; ![^pAEgx
} X n$ZA-
R,G*]/r`
:R,M Y"(
} Ha`N
nf/?7~3?[
}I&.xzJ
/* ZrTB%
**FileAccess.java X+aQ 7^"s
*//文件访问(定位，写) = 'NV3by
package NetFox; hr}f5Z)^v
import java.io.*; ^;RK-)
]alc%(=
cx$IWQf2
public class FileAccessI implements Serializable{ ]a4U\yr
M_};J;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cdt9hH`Cd
RandomAccessFile oSavedFile; l,7& z
long nPos; p0bWzIH
ZOqS"3j! j
x%=CEe?6
public FileAccessI() throws IOException FAEF
{ ]8\I{LR
this("",0); 8u+kA mI
} N s+g9+<A
g0tnt)]
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public FileAccessI(String sName,long nPos) throws IOException YpDJ(61+
{ z6iKIw $
oSavedFile = new RandomAccessFile(sName,"rw"); 25)9R^
this.nPos = nPos; TC?B_;a
oSavedFile.seek(nPos); P9bM+@5e
} $V(]z`b&
TU0-L35P1
D=-}&w_T"
public synchronized int write(byte[] b,int nStart,int nLen) v.Ba
{ jW\:+Taq
int n = -1; [yXmnrxA
try{ HrBJi
oSavedFile.write(b,nStart,nLen); E$)|Kv^
n = nLen; WR)=VE
} ^)Hf%
catch(IOException e) N&NBn(
{ }`B .(3n
e.printStackTrace (); ^HSxE
} @.e X8~3=
>ou=}/<
?{S>%P A_B
return n; HY)xT$/J
} <:v+<)K
8%7%[WC#
&:&89<C'
} ?bB>}:~j)
*p}mn#ru-
gF{ehU%
/* ^3$l!>me
**SiteInfoBean.java qH}8TC
*/ lGd'_~'=
package NetFox; 1MLL
OyZR&,q
JN0h3nZ_
public class SiteInfoBean { + Q-b}
tK%ie\
N)X Tmh2v|
private String sSiteURL; //Site's URL '47 b"uV
private String sFilePath; //Saved File's Path !g|O.mt
private String sFileName; //Saved File's Name b/'bhE=
private int nSplitter; //Count of Splited Downloading File d05xn7%!{
_Je4&KU
}%_|k^t
public SiteInfoBean() Zhq_ pus"a
{//nSplitter的缺省值为5 $D^\[^S
//default value of nSplitter is 5 P8d
this("","","",5); +~^S'6yB
} n[3z_QI
,9P-<P
U**8^:*y#:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "6f`hy
{ +/ukS6>gr
sSiteURL= sURL; {@InOo!4w]
sFilePath = sPath; KZppQ0
sFileName = sName; ?"x4u#x
this.nSplitter = nSpiltter; C}8#yAS9M
"\b>JV5
RQ,#TbAe
} D\Ak-$kJ^
:;+!ID_
\;{ ]YX
public String getSSiteURL() t?GH V3V
{ d51lTGH7Z
return sSiteURL; <Vhd4c
} G^c,i5}w
v Y[s#*+
jrib"Bh3,
public void setSSiteURL(String value) \OwF!~&
{ 9M96$i`P
sSiteURL = value; nGF +a[Z
} op6]"ZV-C
],]Rv#`
fkxkf^g)
public String getSFilePath() 1q}LO2
{ >fBPVu\PA
return sFilePath; OIblBQ!
} Lw>B:3e
[6!k:-t+
}t)+eSUA
public void setSFilePath(String value) Fw<"]*iu
{ -b-a21,m>
sFilePath = value; .zO^"mXjS
} n7!T{+ge
+A3/^C0
$J7V]c*-b
public String getSFileName() ?2<) Jw
{ mfraw2H
return sFileName; $C[z]}iOi
} X7*F~LFrj
46C%at M0}
._}}@V_/
public void setSFileName(String value) u[GZ~L
{ WcN4ff-
sFileName = value; :aNjh
} -<g9) CV5
(p{X.X+
)d3 09O
public int getNSplitter() ,?GwA@~$k:
{ `d_T3^ayu
return nSplitter; T)! }Wvv
} 'm`O34h
7<j!qWm0
Ic/hVKYG5
public void setNSplitter(int nCount) `cGks
{ I-#!mFl
nSplitter = nCount; u+)!C*ho
} mY 1l2
} TNu%_ 34
EavBUX$O
?{J1&;j*
/* +Br<;sW
**Utility.java n_QuuUB
*/ TK5$-6k
package NetFox; K$S0h-?9]O
M^kaik
Za@\=}Tt
public class Utility { f.g!~wGD
Pp?P9s{
Q7+WV`&
public Utility() 9wL2NC31Q
{ 7ZUN;mr
0F$|`v"0
| R,dsBd
} PF4[;ES'
Il=6t
//线程睡眠 >{^_]phlb
public static void sleep(int nSecond) #aqnj+
{ / 4Q=%n
try{ A[P7hMn
Thread.sleep(nSecond); ^A ]4
} IjhRSrCv
catch(Exception e) AH,?B*zGj
{ K'&,]r#
e.printStackTrace (); xU\!UVQ/
} /E6)>y66
} UC&$8^
Q4mtfpiDx
//日志 "5JMk -2k
public static void log(String sMsg) %`~4rf"7
{ >\JPX
System.err.println(sMsg); oIrc))j,$
} ckX8eg!f
BFNO yv
/qQx~doK
public static void log(int sMsg) }cz58%
{ /IirTmFK
System.err.println(sMsg); ZRhk2DA#FF
} )=)N9CRy
} &^ERaPynd
jnV#Q ;
Gr({30"8
/* q~qz^E\T
**TestMethod.java sD3Ts;k
*/ }%KQrlbHJl
package NetFox; "|6(.S+o
>D=X Tgqqq
T#&1q]P1F
public class TestMethod { frbd{o
#o&T$D5
P.(UbF d'
public TestMethod() n l5+#e*\
{ ///xx/weblogic60b2_win.exe m#h`iW
try{ $I5|rB/4?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &Hw:65O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^aaj=p:cV
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4H;g"nWqO
fileFetch.start(); -t_&H\_T
} yc0 1\o
catch(Exception e){e.printStackTrace ();} ^(Gl$GC$Mu
-Ua5anzB
WDNj7
} fTmJDUv+
r%: :q^b3
Xp;'Wa"@
public static void main(String[] args) 6~ET@"0uK
{ ,5 ,r.
new TestMethod(); <,Gjo]z
} %YxKWZ/?
} u9_?c G-
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