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)); 7SHo%bA
} Gg+YfY_
for(int i=0;i<nEndPos.length-1;i++) n\~yX<;X3
{ m|dF30~A
nEndPos = nStartPos[i+1]; rk|a'&
} CjZ6NAHc
nEndPos[nEndPos.length-1] = nFileLength; '#f?#(
} ~~dfpW_"
} IMR$x(g= F
{G.{ad
6QptKXu7
//启动子线程 EG1x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s}!"a8hU`
for(int i=0;i<nStartPos.length;i++) *2:Yf7rvI+
{ mt.,4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4`0;^K.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +-k`x0v
nStartPos,nEndPos,i); 3mA/Nu_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ib(,P3
fileSplitterFetch.start(); -9Xw]I#QR
} p,^>*/O>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dh,7iQ s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |ZuDX87
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \]GGVI;u
nEndPos = " + nFileLength); "b;k.Fx
// fileSplitterFetch[nPos.length-1].start(); Q2R>lzB
~p!QSRu~,b
s.ey!ew
//等待子线程结束 ^ N_`^m
//int count = 0; ZArf;&8
//是否结束while循环 n(# c`t*
boolean breakWhile = false; @f'AWeJ2
;@O(z*14@
%w%zv2d
while(!bStop) JgZdS-~
{ "U{mMd!9L
write_nPos(); qZc)Sa.S
Utility.sleep(500); Ot"(uW4$[
breakWhile = true; dK7 ^
8Nv-/VQ/b
y7 <(,uT
for(int i=0;i<nStartPos.length;i++) /^WE@r[:
{ )xbqQW7%0+
if(!fileSplitterFetch.bDownOver) 7dx4~dF
{ rr6"Y&v
breakWhile = false; Z~B+*HF
break; 1r&AB!Z #
} IT7:QEfKU
} l>33z_H^
if(breakWhile) ";58B}ki
break; _"`/^L`Q?
P:vX }V |[
k.ww-nH
//count++; j[BgP\&,
//if(count>4) !-@SS>
// siteStop(); wf^cyCR0
} _4De!q0(
UvoG<;
0$(jBnE
System.err.println("文件下载结束！"); 4>d[qr*<
} A'w2GC{.
catch(Exception e){e.printStackTrace ();} 4O9tx_<JG
} *,_2hvlz
!DCVoc]pV
LE Jlo%M
//获得文件长度 /Ir 7 DZK
public long getFileSize() 7YSuB9{M
{ ]lC4+{V
int nFileLength = -1; <4SF~i
try{ ~n)]dFy
URL url = new URL(siteInfoBean.getSSiteURL()); gS0,')w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NdaM9a#TZ
httpConnection.setRequestProperty("User-Agent","NetFox"); m}sh I8S
jR}*bIzv
_qdWQFuM
int responseCode=httpConnection.getResponseCode(); ^O?l9(=/u
if(responseCode>=400) Z7ZWf'o
{ aj+zmk~-
processErrorCode(responseCode); : ,|=Q}
return -2; //-2 represent access is error (u$!\fE-et
} c lq <$-
8VKb*
bK6, saN>
String sHeader; an #jZ[
:Fq2x_IUE
ei(|5h
for(int i=1;;i++) R#rh
{ \Gv-sA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s"gKonwI2
//Utility.log(in.readLine()); 15RI(BN
sHeader=httpConnection.getHeaderFieldKey(i); Hd96[Uo
if(sHeader!=null) iFXUKGiV
{ 4d,qXSKty
if(sHeader.equals("Content-Length")) h:eN>yW
{ w`2_6[,9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g5?r9e
break; ~r7DEy|+
} "`H=AX0
} >IR`]
else pU[a[
break; |8b$x| B
} n C\(+K1%
} =aX1:Z
catch(IOException e){e.printStackTrace ();} OsDp88Bc
catch(Exception e){e.printStackTrace ();} bUpmU/RW
f4qS OVv
w`w `q'
Utility.log(nFileLength); \f~u85
LD7? .
w;g)Iy6x
return nFileLength; O p!
} <<~lV5
^*j[&:d
j58Dki->.
//保存下载信息（文件指针位置） PkZf(=-X
private void write_nPos() 6T5A31 Q
{ %`8KG(F^
try{ AiR%MD
output = new DataOutputStream(new FileOutputStream(tmpFile)); c9>8IW
output.writeInt(nStartPos.length); j X^&4f
for(int i=0;i<nStartPos.length;i++) !c3Qcva
{ vgd}09y
// output.writeLong(nPos); loAfFK>g
output.writeLong(fileSplitterFetch.nStartPos); (dw3'W
output.writeLong(fileSplitterFetch.nEndPos); OoA5!HEh
} g%KGF)+H
output.close(); 5G dY7t_1
} t\E-6u
catch(IOException e){e.printStackTrace ();} Iltg0`
catch(Exception e){e.printStackTrace ();} S0X.8Bq
} ^$T!@+:
&z1|
^loF#d=s
//读取保存的下载信息（文件指针位置） |R:v<
private void read_nPos() ~50y-
{ BdRE*9.0
try{ FN8=YUYK%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o>QFdx
int nCount = input.readInt(); PAO[Og,-
nStartPos = new long[nCount]; H@OrX
nEndPos = new long[nCount]; C_g"omw40
for(int i=0;i<nStartPos.length;i++) rA>A=,
{ fS'k;r*r
nStartPos = input.readLong(); +A.a~Stt
nEndPos = input.readLong(); @8x6#|D
} 3e!a>Gl*
input.close(); UlLM<33_)
} JXD?a.vy^q
catch(IOException e){e.printStackTrace ();} 2!"\;/
catch(Exception e){e.printStackTrace ();} O_%PBgcJr
} @pEO@bbg>
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0YTtA]|`4
private void processErrorCode(int nErrorCode) -sGWSC
{ {R6Zwjs
System.err.println("Error Code : " + nErrorCode); hIg, 0B
} .P0Qs&i
?Pok-90
c=U$$|qHV
//停止文件下载 6#lC(ko'
public void siteStop() $=S'#^Z
{ cVv4gQD\
bStop = true; (tz_D7c$F
for(int i=0;i<nStartPos.length;i++) 8 MACbLY
fileSplitterFetch.splitterStop(); WPh |~]by<
m}'t'l4 c
6=`m
} kxKnmB#m-
} aZ`_W|
//负责部分文件的抓取 olQ8s*
**FileSplitterFetch.java odn97,A
*/ ^QL/m\zq@%
package NetFox; OKLggim{
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JWm^RQ
import java.io.*; fuIv,lDA
import java.net.*; \Z7([Gh
o\:f9JL
=-s20mdj
public class FileSplitterFetch extends Thread { f 7QUZb\
M b /X@51
$'mB8 S
String sURL; //File URL Ubos#hP
long nStartPos; //File Snippet Start Position gPhw.e""
long nEndPos; //File Snippet End Position +e3WwUx
int nThreadID; //Thread's ID o-e,
boolean bDownOver = false; //Downing is over [C~)&2wh>
boolean bStop = false; //Stop identical 35]G_\
FileAccessI fileAccessI = null; //File Access interface >cr_^(UW&
zL!~,B8C
(gJ )]/n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .8uwg@yD
{ Dy!bj
this.sURL = sURL; 5}l#zj
this.nStartPos = nStart; 7)6Yfa]I%
this.nEndPos = nEnd; lVp~oZC6[
nThreadID = id; h9OL%n 7m'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +qW w-8
} :Kc0ak)<n
1&dsQ,VDl
|% YzGgp7
public void run() :,z3:PL
{ zt>_)&b
while(nStartPos < nEndPos && !bStop) _2Xu1q.6~5
{ _=^hnv
U"Ob@$ROFy
LkZo/K~
try{ He_(JXTP
URL url = new URL(sURL); $?JLCa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'V9aB5O&
httpConnection.setRequestProperty("User-Agent","NetFox"); E<G@LT
String sProperty = "bytes="+nStartPos+"-"; i7!mMO8]
httpConnection.setRequestProperty("RANGE",sProperty); ZT6X4 Z
Utility.log(sProperty); :iOHc-x
gW pT:tX-
qLi1yH
InputStream input = httpConnection.getInputStream(); 9xS`@ "`
//logResponseHead(httpConnection); ;>8TNB e!
@p` CAB
JE:n`l/p
byte[] b = new byte[1024]; zam0(^=
int nRead; gl\$jDC9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zow^bzy4
{ !m:PBl5
nStartPos += fileAccessI.write(b,0,nRead); 4l!Yop0h
//if(nThreadID == 1) Y l3[~S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'UG}E@G
} ]!J3?G
{$TB#=G
~TK^aM
Utility.log("Thread " + nThreadID + " is over!"); l:Xf(TLa
bDownOver = true; Nb9V/2c;V
//nPos = fileAccessI.write (b,0,nRead); OVo
} Jz3<yQ-
catch(Exception e){e.printStackTrace ();} e]B<\i\T
} LY cSMuJ
} 64?$TT
3!w>"h0(
@`+$d=rO`
//打印回应的头信息 Cy> +j{%!
public void logResponseHead(HttpURLConnection con) <[f2ZS6
{ ~U*N'>'=)
for(int i=1;;i++) VGUDUM.8
{ 714nUA872
String header=con.getHeaderFieldKey(i); e4H0<h }{
if(header!=null) e%0#"6}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OZ0%;Y0
Utility.log(header+" : "+con.getHeaderField(header)); Tvw2py q
else 1~u\]Zi=D
break; `xAJy5
} xr3PO?:
} 1Y"qQp
Ri6 br
c1!/jTX$
public void splitterStop() jG ;(89QR/
{ b0=AQ/:
bStop = true; jL).B&
} @.@#WHde
i-vJ&}}
tsC|R~wW
} eKti+n.
VP[!ji9P
5$Q`P',*Ua
/* %c2i.E/G
**FileAccess.java "/-v 9
*//文件访问(定位，写) x[@3;_'K
package NetFox; QAnfxt6
import java.io.*; R/xCS.yl}
{Qmb!`F
/2V',0
public class FileAccessI implements Serializable{ Wv/5#_
ea}KxLC`,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;|1P1H-W~M
RandomAccessFile oSavedFile; r_Yl/WW
long nPos; `a-T95IFy
'n.9qxY;
$=SYssg7La
public FileAccessI() throws IOException WY~[tBi\
{ 1L qJ@v0
this("",0); rL/7wa
} He;%6OG{
]H'82a
ddhTri'f
public FileAccessI(String sName,long nPos) throws IOException 3evfX[V#
{ \gv x)S11
oSavedFile = new RandomAccessFile(sName,"rw"); ?o'arxCxZn
this.nPos = nPos; qc"/T16M]
oSavedFile.seek(nPos); yVv3S[J
} Z'bMIdV
%--5bwZi
4\WkXwoqQO
public synchronized int write(byte[] b,int nStart,int nLen) buyz>ICP
{ vrx3O
int n = -1; CnA)>4E*'
try{ emIbGkH
oSavedFile.write(b,nStart,nLen); Pg C]@Q%
n = nLen; G"sc;nT
} m4LM10
catch(IOException e) RA67w&
{ E?o8'r
e.printStackTrace (); pra&A2Y\
} +mv%z3"j;
b#j5fEY
#T`+~tW'|
return n; j".6
} [+7X&B
[kkcV5I-
n}kz&,
} D|#(zjl@
?y@pRe$2
'2{o_<m
/* nE%qm -
**SiteInfoBean.java V7i`vo3Cc
*/ hIr^"kVK
package NetFox; ~Nh7C b_
o-Arfc3Q
;H|M)z#[Z
public class SiteInfoBean { 5LH ]B
q8]k]:r
#TF
private String sSiteURL; //Site's URL D$ z!wV
private String sFilePath; //Saved File's Path C}E ea~
private String sFileName; //Saved File's Name \ .s".aA
private int nSplitter; //Count of Splited Downloading File X/749"23
7s3<}
Nuq/_x
public SiteInfoBean() XL9lB#v^
{//nSplitter的缺省值为5 a8$pc>2E
//default value of nSplitter is 5 7J/3O[2
this("","","",5); th|Q NG
} aX:$Q }S
6* w;xf
_ RT}Ee}Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nzDY!Y
{ mn` Ae=
sSiteURL= sURL; HEN9D/O=
sFilePath = sPath; U%l{>*q
sFileName = sName; (Cd`~*5
this.nSplitter = nSpiltter; ,r4af<
a@1gMZc*
`rQl{$9IC
} ? GW3E
e0 EJ[bG
F4Z0g*^x
public String getSSiteURL() ,/9|j*9H
{ Jq)k?WS
return sSiteURL; x|5/#H
} 5Px_vtqP
Xw5"JE!.
i[J',
public void setSSiteURL(String value) %R>MSSjvr
{ VvKH]>*
sSiteURL = value; `#U6`[[
} +__Rk1CVh
S0yT%V
na)ceN2h
public String getSFilePath() T94$}- 5/)
{ 1qF.0
return sFilePath; XwMC/]lK<
} 1cega1s3xR
HR
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public void setSFilePath(String value) 24fWj?A|^
{ { q<l]jn9
sFilePath = value; f^ qQ5N
} TmiQq'm[b
[XK"$C]jHJ
&5<lQ1
public String getSFileName() EbHeP
{ 2$=HDwv
return sFileName; @hPbD?)M
} Ja1*a,],L
mHy]$Z
2BY:qz%:
public void setSFileName(String value) lhU#/}Z
{ &D#v0!e~x
sFileName = value; X(9Ff=0.~
} EzaOg|
~MX@-Ff
^y,ip=<5\3
public int getNSplitter() 3ssio-X
{ p"Y=
return nSplitter; H Vy^^$
} 0a5P@;"a
MRc^lYj{
19_F\32
public void setNSplitter(int nCount) 5YasD6l
{ zD'gGxM1
nSplitter = nCount; Jo ^o`9
} ?}.(k/
} {U9jA_XX
Df9}YI;?
Bv3v;^
/* ;DTNw=
**Utility.java <Jx{Uv
*/ "O`;zC
package NetFox; ?W(f%/B#
yLP0w^Q
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public class Utility { IP3-lru
>*MB_m2|
6dh PqL
public Utility() Velmq'n
{ foeVjL:T
1 /`>Eh
Dcf`+?3
} [Zf<r1m
Jc+U$h4
//线程睡眠 3^\y>
public static void sleep(int nSecond) Y'P8`$
{ {BF\G%v;+
try{ S.z;Bm
Thread.sleep(nSecond); 7)T+!>
} b#M<b.R)
catch(Exception e) *QVE>{
{ \r2w@F{C
e.printStackTrace (); T]xGE
} =%p"oj]:
} M\%{!Wzo8
ocMf}"
//日志 4R]|
public static void log(String sMsg) >h9U~#G=
{ tv0xfAV
System.err.println(sMsg); g 0L 4
} <j>@Fg#q
,-Na'n
wcOAyo5(n
public static void log(int sMsg) $2.DZ
{ z(xvt>
System.err.println(sMsg); 8P 8"dN[
} $#!~K2$
} #SdaTMLFf
86Rit!ih
VlEkT9^:
/* & 2bf
**TestMethod.java R8KL4g-d
*/ ><=af 9T
package NetFox; [Xrq+O,
cE3co(j
5IepVS(>?v
public class TestMethod { g^idS:GtX5
;9~z_orNQZ
}yw\+fc
public TestMethod() {*2A%}S
{ ///xx/weblogic60b2_win.exe U{x'@/Ld
try{ kB 2bT}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sw&Qks?V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v6GWD}HH,
SiteFileFetch fileFetch = new SiteFileFetch(bean); u32<=Q[
fileFetch.start(); zb<+x(0y"
} &$=F$
catch(Exception e){e.printStackTrace ();} WM#!X!Vo
AIeYy-f
@.0,ka,X
} "n\!y~:
&.}zZ/
] !H<vR$8
public static void main(String[] args) H\S,^)drJ?
{ 29GiNy+ob
new TestMethod(); m4iR '~L}
} ]mc,FlhU@
} h3:,Gbyap
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