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)); _0: }"!Gq
} GoTJm}[NP
for(int i=0;i<nEndPos.length-1;i++) l6O8:XI
{ Y&JK*d
nEndPos = nStartPos[i+1]; a][QY1E@?
} wSwDhOX=
nEndPos[nEndPos.length-1] = nFileLength; xJSK"
} W$bQS!7y
} EBl?oN7E
dqu+-43I|
DtrR< &m
//启动子线程 q+}KAk|]V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $VRVMY [q
for(int i=0;i<nStartPos.length;i++) !CO1I-yL
{ |>U:Pb(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sq Y$\&%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?!Bf# "TY
nStartPos,nEndPos,i); mIy|]e`SJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <*'%Xgm
fileSplitterFetch.start(); Gi=s|vt
} ]dj W^C]94
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CfMCc:8mL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {Jx-Zo>'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |0Y: /uL#)
nEndPos = " + nFileLength); 7yM"G$
// fileSplitterFetch[nPos.length-1].start(); eGF+@)K1"
X{YY)}^
1;8%\r[|5^
//等待子线程结束 R5KOai!
//int count = 0; ^/V>^9CZ
//是否结束while循环 >L_nu.x
boolean breakWhile = false; q<Sb>M/\,
gFQ\zOlY8a
f}%paE"
while(!bStop) :Ou[LF.O
{ b:6NVHb%
write_nPos(); f2f2&|7
Utility.sleep(500); (.Th?p%>7
breakWhile = true; vi1 D<
)oU%++cdo
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for(int i=0;i<nStartPos.length;i++) 'K7m!y
{ 9z9\pXFQ
if(!fileSplitterFetch.bDownOver) &Fg|52
{ bMp[:dw`y
breakWhile = false; rQb=/@-
break; \fD)|
} 5HqvSfq>?
} !CGpE=V
if(breakWhile) Z&![W@m@0N
break; A6Vb'Gqv{
S8Ec.]T
9(AY7]6
//count++; `$oy4lDKQ
//if(count>4) p`I[3/$3
// siteStop(); m*f"Y"B.1I
} R$;TX^r'o&
\jx3Fs:Q
mp z3o\n
System.err.println("文件下载结束！"); ~JO.h$1C
} <jBRUa[j_
catch(Exception e){e.printStackTrace ();} @4n>I+6*&
} Z}.ZTEB
Z{1B:aW
9+3 VK
//获得文件长度 BlqISyrY
public long getFileSize() c7RQ7\
{ iU AY
int nFileLength = -1; my#\(E+
try{ R[@}Lg7+v
URL url = new URL(siteInfoBean.getSSiteURL()); Zpz3?VM(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ilAhw4A
httpConnection.setRequestProperty("User-Agent","NetFox"); d0;?GQYn:
V)P8w#,
<,\U,jU_
int responseCode=httpConnection.getResponseCode(); ^9kx3Pw?8
if(responseCode>=400) 4eJR=h1
{ (p<pF].
processErrorCode(responseCode); }b/P\1#z
return -2; //-2 represent access is error Nnq1&j"m
} iUk#hLLC
(%mV,2|:20
Z58{YCY
String sHeader; ]J@-,FFC
D"%>
I5 qrHBJ >
for(int i=1;;i++) l]OzE-*$b
{ z"Mk(d@-E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m"QDc[^Ge
//Utility.log(in.readLine()); Xt +9z
sHeader=httpConnection.getHeaderFieldKey(i); Q!_d6-*u
if(sHeader!=null) (>NZYPw^3
{ aemi;61T\
if(sHeader.equals("Content-Length")) +}PN+:yV
{ Je}0KW3G9L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @_1cY#!
break; m.<u!MI
} Qxk& J
} o4wSt6gBcJ
else @0d"^
break; MzDosr3:
} b'Km-'MtH
} "p7nngn~
catch(IOException e){e.printStackTrace ();} y G3aF(
catch(Exception e){e.printStackTrace ();} B{*{9!(l9
Gr#3GvL
(|NCxey
Utility.log(nFileLength); lqKj;'
#'0Yzh]qc
6q6xqr:W
return nFileLength; *QV"o{V
} ambr}+}
,Vw>3|C
hS&l4 \I'Z
//保存下载信息（文件指针位置） ,~DV0#"
private void write_nPos() ZvMU3])u
{ um}q@BU
try{ &BRa5`
output = new DataOutputStream(new FileOutputStream(tmpFile)); iaLZ|\`3a
output.writeInt(nStartPos.length); PjH'5Y
for(int i=0;i<nStartPos.length;i++) Wky9wr:g
{ -$DfnAh
// output.writeLong(nPos); 2`TV(U@
output.writeLong(fileSplitterFetch.nStartPos); c+ e~BN
output.writeLong(fileSplitterFetch.nEndPos); AV7#,+p%G
} Fk^N7EJ:$
output.close(); *UJ4\
} }>d
catch(IOException e){e.printStackTrace ();} ,Aai-AGG@
catch(Exception e){e.printStackTrace ();} {M5t)-
} {_/o' 6
/;Hr{f jl{
~f[ Y;
//读取保存的下载信息（文件指针位置） k5Fj"U
private void read_nPos() kwL|gO1L
{ 7eju%d
try{ >7zC-3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *tgu@9b
int nCount = input.readInt(); tW/g0lC%
nStartPos = new long[nCount]; 8|)^m[c&
nEndPos = new long[nCount]; F"UI=7:o
for(int i=0;i<nStartPos.length;i++) 40pz<-B
{ ;81,1 Ie<~
nStartPos = input.readLong(); 8-B7_GoJ+B
nEndPos = input.readLong(); c!/+0[
} v"W*@7<`S
input.close(); zQG{j\
} `Z8k#z'bN
catch(IOException e){e.printStackTrace ();} 1l"2 ~k
catch(Exception e){e.printStackTrace ();} r PK.Q)g
} bWAa: r
7J!s"|VS
FK593z
private void processErrorCode(int nErrorCode) | @$I<
{ .<F46?HS
System.err.println("Error Code : " + nErrorCode); `SsoRPW&$
} 7XK0vKmW3
8hD[z}
Cj<8r S4+
//停止文件下载 tP7<WGHd/
public void siteStop() {MSE}|A\V
{ 4P k%+l
bStop = true; XFvl
for(int i=0;i<nStartPos.length;i++) L_RVHvA=M/
fileSplitterFetch.splitterStop(); 6UuN-7z!"
]LUcOR
tVEe)QX
} ws+'*7
} ^`'\eEa
//负责部分文件的抓取 o+'|j#P
**FileSplitterFetch.java 5P%#5Yr2
*/ d#a/J.Z$A
package NetFox; Y=O+d\_W
rR-[CT
M|mfkIk0MB
import java.io.*; ]}XDDPbZ}
import java.net.*; $Gv@lZ@=
ld@+p
eIY`RMo (
public class FileSplitterFetch extends Thread { /*T^7Y&
"TZY)\{L
"!V`_ S;
String sURL; //File URL ]s AuL!
long nStartPos; //File Snippet Start Position Z%]K,9K
long nEndPos; //File Snippet End Position G?'^"ae"Z
int nThreadID; //Thread's ID r|u[36NmA
boolean bDownOver = false; //Downing is over zR?R,k)m
boolean bStop = false; //Stop identical jRU:un4
FileAccessI fileAccessI = null; //File Access interface N*}soMPV^.
N68$b#9Ry
k`8O/J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t4_yp_
{ <@KIDZYC
this.sURL = sURL; <&l$xn
this.nStartPos = nStart; ~p?ArZb
this.nEndPos = nEnd; XNWtX-[^@
nThreadID = id; e^>>"tr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~3?-l/$
} V%r`v%ktF
!q\=e@j-i
S F*C'
public void run() <v|"eq}
{ 4k<o
while(nStartPos < nEndPos && !bStop) @)6b
{ Lc{arhN
@"MYq#2c$
M/=36{,w-
try{ ly17FLJ].
URL url = new URL(sURL); P\7*ql`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FT-.gi0
httpConnection.setRequestProperty("User-Agent","NetFox"); )bOfs*S
String sProperty = "bytes="+nStartPos+"-"; GHcx@||C?
httpConnection.setRequestProperty("RANGE",sProperty); 5lG\Z?
Utility.log(sProperty); at_*Zh(
'Z4}O_5_
]u|v7}I4
InputStream input = httpConnection.getInputStream(); f47]gtB-
//logResponseHead(httpConnection); EVX3uC}{
ju{Y6XJ)
B-rE8\
byte[] b = new byte[1024]; b?i+nhqI
int nRead; CvY+b^;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g%f5hy
{ *#XZ*Ga
nStartPos += fileAccessI.write(b,0,nRead); &L+uu',M0c
//if(nThreadID == 1) \Mg_Q$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1n8[fgz
} H~+A6g]T
z!"vez
4|`>}Nu
Utility.log("Thread " + nThreadID + " is over!"); \9VF)Y.ke
bDownOver = true; Q6qW?*Y
//nPos = fileAccessI.write (b,0,nRead); (4+P7Z,Nc
} \sAaVdZJH(
catch(Exception e){e.printStackTrace ();} 'ztOl`I5V
} lI=<lmM0|/
} (SBhU:^h
90<g=B
{-\U)&6#v
//打印回应的头信息 MNd\)nX
public void logResponseHead(HttpURLConnection con) ."$t&[;s
{ -eG~
for(int i=1;;i++) %lHHTZ{+
{ G tI )O}
String header=con.getHeaderFieldKey(i); :25LQf^nz
if(header!=null) 7Bp7d/R-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y!#-[K:
Utility.log(header+" : "+con.getHeaderField(header)); rL{R=0
else !{lH*
break; XDemdMy$
} Z10Vx2B
} k7CKl;Fck
|"gL{De
y@3p5o9lv-
public void splitterStop() t%lat./yT
{ rm[C{Pn
bStop = true; >$4#G)s
} $d?W1D<A
G\@pg;0|y
ljKIxSvCFp
} m-Eh0Zl>Z
dz_S6o ]
R*[sO*h\k
/* =fcg4h5(
**FileAccess.java KxkBP/`3Q
*//文件访问(定位，写) b7QE
package NetFox; Za:j;u Y
import java.io.*; 1r;zA<<%R
*&NP?-E
:o'x?]
public class FileAccessI implements Serializable{ `L'g<VK;
RxP H[7oZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yix[zfQt0
RandomAccessFile oSavedFile; 6zi>Q?] 1
long nPos; <CyU9`ye
]q]xU,
n=.P46|
public FileAccessI() throws IOException G!q[NRu
{ G*CPj^O
this("",0); W7S~~
} FnO@\{M"A
UkL1h7}a\
R BYhU55B
public FileAccessI(String sName,long nPos) throws IOException o`bc/3!
{ Og\k5.! ,
oSavedFile = new RandomAccessFile(sName,"rw"); 9bM\ (s/
this.nPos = nPos; <Riz!(G
oSavedFile.seek(nPos); Ir9GgB
} Met]|&
V@ >(xe7
Cr.YSWg)4
public synchronized int write(byte[] b,int nStart,int nLen) 0,%{r.\S
{ KF.{r
int n = -1; 4{P+p!4
try{ "_{NdV|a
oSavedFile.write(b,nStart,nLen); /I%z7f91O
n = nLen; n4K!Wv&u
} \Vyys[MMY8
catch(IOException e) #<*Vc6pC
{ ~t6q-P
e.printStackTrace (); $^]K611w9
} =Hi@q "
^hIdmTf6
Z8|<%1Kge
return n; }v ZOPTP
} *1)>He$qL
GJ ^c^`
WK{`_c U^
} 51|ky-
~>u.d
cQU/z"?+
/* EeuYRyK
**SiteInfoBean.java xRh 22z
*/ jZXa R
package NetFox; aO'#!k*R
N^L@MR-
8x{Owj:Q
public class SiteInfoBean { .biq)Le
4#$#x=:
? #K|l*
private String sSiteURL; //Site's URL ]E`<8hRB
private String sFilePath; //Saved File's Path Pe,>ny^J1
private String sFileName; //Saved File's Name lTx_E#^s
private int nSplitter; //Count of Splited Downloading File ^m>4<~/
^6s im2
c!6D{(sfh
public SiteInfoBean() Itl8#LpLM
{//nSplitter的缺省值为5 l1+l@r\
//default value of nSplitter is 5 f"MID6
this("","","",5); +:MSY p
} - x
$RD~,<oEm
v] m/$X2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -,J<X\
{ {2\Y%Y'}*
sSiteURL= sURL; R<|\Z@z
sFilePath = sPath; SI7rTJ]/
sFileName = sName; 1NZ"\9=U
this.nSplitter = nSpiltter; F y+NJSG
n$iX6Cd
=?i?-6M
} &W<7!U:2m
#ArrQeO 5_
6h:QSVfx
public String getSSiteURL() n Bu!2c
{ ?@64gdlwq
return sSiteURL; H/,KY/>i
} eaw!5]huu
^m\o(R
Kd\0nf6
public void setSSiteURL(String value) 1/DtF
{ j\y;~ V
sSiteURL = value; Ymut]`dX
} @C;1e7
+f3Rzx]
opcanl9pSW
public String getSFilePath() Hm-#Mpw
{ Xoj"rR9|
return sFilePath; !>`Q]M`
} mF7Ak&So^
G~9m,l+
]2AOW}=
public void setSFilePath(String value) @Z5q2Q
{ k/K)nH@)
sFilePath = value; RXgb/VR
} AWO)]rM
[txOh!sxD
;UdM8+^/V]
public String getSFileName() B,>02EZ
{ V DFgu
return sFileName; vq$6e*A
} `PWKA;W$0
yV^Yp=f_
4]d^L>
public void setSFileName(String value) IwyA4Ak Ru
{ wkg4I.
sFileName = value; |#Gxqq'
} -gn0@hS0
!=9x=
so-5%S
public int getNSplitter() 'Ru(`" 1|
{ qCs/sW
return nSplitter; I%T+H[,
} pbMANZU[
(,Y[2_Zv
{lI}a8DP
public void setNSplitter(int nCount) 6)INr,d
{ YvY|\2^K
nSplitter = nCount; =z1Lim-
} ~ #jQFyOh
} H%_^Gy8f
7oZ:/6_>
\u[x<-\/6
/* &V38)83a
**Utility.java H<Snp)
*/ SmXoNiM"y
package NetFox; Z-@nXt
Aztrq
|Ajd$+3
public class Utility { z"@^'{.l
9q;O`&
!BQt+4G7
public Utility() $QJ3~mG2
{ *i"9D:
xm m,-u
o/AG9|()4
} ~j!n`#.\
i"Jy>'
//线程睡眠 P\"kr?jZP
public static void sleep(int nSecond) T?3Q<[SmI
{ J=A)]YE
try{ [S6u:;7
Thread.sleep(nSecond); fUw:jExz
} }?[];FB
catch(Exception e) gM96RY
{ NaR} 0
e.printStackTrace (); t{})6
} ,,H5zmgA
} VDxm|7
EX)&|2w
//日志 Ez1eGPVr
public static void log(String sMsg) 9<mMU:
{ Wn<?_}sa|z
System.err.println(sMsg); A7 RI&g v5
} *HrEh;3^J
}*x1e_m}H
b(K"CL\p
public static void log(int sMsg) /k.0gYD
{ 'FW?
System.err.println(sMsg); #*(}%!rD*
} ;4O[/;i
} OVLVsNg
rS@/@jKZE
[6VB&
/* Z`TfS+O6
**TestMethod.java 1/$PxQ
*/ -2hirA<^
package NetFox; c>bns/f
! ._q8q\
&}DfIP<
public class TestMethod { y##h(y
.}__XWK5
CW1l;uwtU
public TestMethod() 9p_?t'&>q
{ ///xx/weblogic60b2_win.exe @a8lF$<
try{ Tm"H9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oidZWy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b0~r/M;J
SiteFileFetch fileFetch = new SiteFileFetch(bean); '_v~+
fileFetch.start(); V%-hP~nyBx
} fe\lSGmf
catch(Exception e){e.printStackTrace ();} >a8iY|QY
[8QK @5[
# ~<]z
} 1I%u)[;>
\[9VeqMU
)^:H{1'
public static void main(String[] args) m]qw8BoU`F
{ A-Ba%Fv
new TestMethod(); :jTSOd[r
} O84]J:b
} hQ#e;1uD
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