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)); !^FR a{b
} (=eJceE!
for(int i=0;i<nEndPos.length-1;i++) P =jRof$
{ wa f)S=
nEndPos = nStartPos[i+1]; ":meys6t#
} Gkr?M^@K
nEndPos[nEndPos.length-1] = nFileLength; }9FAM@x1K&
} oz[Mt i*
} H-g CY|W
|3SM
"+{>"_KV
//启动子线程 9ZVzIv(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; # ^q87y
for(int i=0;i<nStartPos.length;i++) ,g~Iup
{ Kwmtt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F39H@%R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 921m'WE
nStartPos,nEndPos,i); M}Obvl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )&F]j
fileSplitterFetch.start(); HVLj(_ A
} 9V0@!M8S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H(rK39Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ENhKuX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z^z,_?q;
nEndPos = " + nFileLength); 0Uf.aP
// fileSplitterFetch[nPos.length-1].start(); )xxpO$
\ y}!yrQ
_+*+,Vx
//等待子线程结束 vP.^j7wB
//int count = 0; \&jmSa=]l
//是否结束while循环 :+?w>
boolean breakWhile = false; NQu.%=
(aUdPo8H^
d [f,Nu'
while(!bStop) sn.0`Stt
{ *2^+QKDG
write_nPos(); |1/UC"f
Utility.sleep(500); ;%`oS.69
breakWhile = true; qdQQt5Y'm
98ot{+/LK
p*5QV
for(int i=0;i<nStartPos.length;i++) P ?A:0a
{ Muay6b?
if(!fileSplitterFetch.bDownOver) WXmR{za
{ d$}!x[g$Z
breakWhile = false; @ i*It Hk
break; pW,)yo4
} 7 /7,55
} $TZjSZ1w
if(breakWhile) #e*jP&1S
break; 9%& =n
?K!^[aO}=
/t|Lu@&:Xo
//count++; HOSt0IHzty
//if(count>4) c_ Dg0
// siteStop(); bD:[r))#e
} $GJuS^@%
&$NYZ3?9
/3KPK4!m
System.err.println("文件下载结束！"); O-,0c1ts
} !eP)"YWI3
catch(Exception e){e.printStackTrace ();} $_Kcm"oj
} Yj{-|2YzL
E'iN==p_:
m/bP`-/,
//获得文件长度 EN-;@P9;C
public long getFileSize() H/''lI{k)
{ $VNj0i. Pr
int nFileLength = -1; yR$ld.[uf
try{ jzb%?8ZJ
URL url = new URL(siteInfoBean.getSSiteURL()); |6o!]~&e$1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pybE0]
httpConnection.setRequestProperty("User-Agent","NetFox"); #<o=W#[
X4dxH_@
n]x%xnt
int responseCode=httpConnection.getResponseCode(); 8~j1
if(responseCode>=400) k}hTSL
{ G<W;HMj2
processErrorCode(responseCode); m'PU0x
return -2; //-2 represent access is error i1JVvNMQ,
} 0?Bv zfb
>)*0lfxTZ
OSY.$$IO
String sHeader; M"s+k
>XJUj4B|X
BIY"{"hJ
for(int i=1;;i++) `_+%
{ pQCocy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PR3&LI;B*
//Utility.log(in.readLine()); PdqyNn=
sHeader=httpConnection.getHeaderFieldKey(i); ZE:!>VXa87
if(sHeader!=null) QruclNW{Bv
{ ?^gq
if(sHeader.equals("Content-Length")) {JlSfJw!
{ qtlcY8!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L]Dq1q8`
break; A/TCJ#>l
} CNl @8&R
} wBI>H 7A
else A/sM ?!p>_
break; 3,yzRb
} tRVz4fk[G
} lnQY_~s
catch(IOException e){e.printStackTrace ();} IBYSI0
catch(Exception e){e.printStackTrace ();} a98J_^n
P^^WViVX
{wh, "Ok_
Utility.log(nFileLength); GQ\;f
gaWJzK Yc_
i)q8p
return nFileLength; *X\J[$!
} :6jh*,OHZl
1!W'0LPM
/N7.|XI.
//保存下载信息（文件指针位置） :YCB23368"
private void write_nPos() 0BPUbp(
{ 2?nEHIUT
try{ cnz+%Y N
output = new DataOutputStream(new FileOutputStream(tmpFile)); '1"vwXJ"
output.writeInt(nStartPos.length); v(P5)R,
for(int i=0;i<nStartPos.length;i++) g+]o=@
{ iI Dun Ih
// output.writeLong(nPos); ,FL*Z9wA
output.writeLong(fileSplitterFetch.nStartPos); 3YD.Fjz$
output.writeLong(fileSplitterFetch.nEndPos); xQDWnpFc
} gTb%c84
output.close(); .~,=?aq^
} -T2w?|
catch(IOException e){e.printStackTrace ();} O"~CZh,:r}
catch(Exception e){e.printStackTrace ();} KnC:hus
} ZVz`g]
_sK{qQxvM=
$1Qcz,4B|
//读取保存的下载信息（文件指针位置） yY_#fJj
private void read_nPos() zuS4N?t`p
{ uc Ph*M
try{ B &e'n<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *~kHH
int nCount = input.readInt(); |f3 :9(p
nStartPos = new long[nCount]; O,Ej m<nt
nEndPos = new long[nCount]; s"~3.J
for(int i=0;i<nStartPos.length;i++) O+"a0:GM
{ 3(`P x}
nStartPos = input.readLong(); rGlnu.mK^
nEndPos = input.readLong(); n;LjKE
} a FL;E
input.close(); a5?Yh<cJ
} a= (vS
catch(IOException e){e.printStackTrace ();} \Vx_$E
catch(Exception e){e.printStackTrace ();} 1ZY~qP+n+
} wwE3N[
.u:aX$t+
:6J&%n
private void processErrorCode(int nErrorCode) R(f6uO!m
{ @?*; -]#)
System.err.println("Error Code : " + nErrorCode); ^$s&bH'8
} y I}>
}H:wgy`
LZDJ\"a-
//停止文件下载 INY?@in
public void siteStop() rE%HNPO
{ h_5CWQSi
bStop = true; 2 ZyO
for(int i=0;i<nStartPos.length;i++) oQ}K_}{>
fileSplitterFetch.splitterStop(); 9qvl9,*g
8cGoo u6
Ey)ey-'\
} D2I|Z
} 0UhJ I
//负责部分文件的抓取 7Y5.GW\^
**FileSplitterFetch.java N(%(B
*/ ZF@$3
package NetFox; Of>2m<
\. a7F4h
O9rA3qv B
import java.io.*; sGx3O i
import java.net.*; 5zz">-Q !
>qZl s'
gxmY^"Jy
public class FileSplitterFetch extends Thread { 06z+xxCo
aSMoee@!
hQeG#KQ
String sURL; //File URL Ax*xa6_2
long nStartPos; //File Snippet Start Position mrBK{@n
long nEndPos; //File Snippet End Position <R?S
int nThreadID; //Thread's ID u.Tknw-X
boolean bDownOver = false; //Downing is over s8dP=_ `
boolean bStop = false; //Stop identical Z1_F)5pn
FileAccessI fileAccessI = null; //File Access interface :eIQF7-
0i>p1/kv
~ ReX$9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >[l2KD
{ Y h53Z"a
this.sURL = sURL; J-qUJX~4c
this.nStartPos = nStart; S6Y:Z0
this.nEndPos = nEnd; $\q.Zb
nThreadID = id; f)mOeD*u|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DFvGc`O4
} "^)GnK +-
b[J0+l\!"
/=g/{&3[a>
public void run() -Jt36|O
{ Z!3R
while(nStartPos < nEndPos && !bStop) 8nwps(3
{ r7FJqd
TfHL'u9B
4s@Tn>%SP
try{ ^SK!?M
URL url = new URL(sURL); *c 9S.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /vC!__K9:
httpConnection.setRequestProperty("User-Agent","NetFox"); }X. Fm'`
String sProperty = "bytes="+nStartPos+"-"; @^/aS;B$>
httpConnection.setRequestProperty("RANGE",sProperty); ^7yaMB!
Utility.log(sProperty); hkdF
FY`t7_Y?GV
$%4<q0-
InputStream input = httpConnection.getInputStream(); CbpzYv32
//logResponseHead(httpConnection); Qq'e#nI@
GWLdz0`2_
=~5N/!
byte[] b = new byte[1024]; 5H1N]v+
int nRead; _l+C0lQl=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &xZSM,
{ f8ZuG !U
nStartPos += fileAccessI.write(b,0,nRead); U8-OQ:2.
//if(nThreadID == 1) HD& Cp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T2_iH=u
} ?#Y:2LqPC
R x(yn
;G[0%z+*
Utility.log("Thread " + nThreadID + " is over!"); ;WAa4r>
bDownOver = true; 4I .'./u
//nPos = fileAccessI.write (b,0,nRead); EwmNgmYq
} I9m9`4BK
catch(Exception e){e.printStackTrace ();} }9glr]=
} jGT|Xo>t
} hA;Ai:8
3V7WIj<
R+_!FnOJ
//打印回应的头信息 yz,0 S'U
public void logResponseHead(HttpURLConnection con) H_Xk;fM
{ uUV"86B_
for(int i=1;;i++) , &n"#
{ XE&h&v=>
String header=con.getHeaderFieldKey(i); |KVVPXtq%C
if(header!=null) <sw=:HU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A3*(c3
Utility.log(header+" : "+con.getHeaderField(header)); NCY2^
else hn\d{HP
break; h-RhmQA=Iz
} Sk)lT^by
} (&v,3>3]
}!?RB v'W
Gs,e8ri!
public void splitterStop() f/s"2r
{ UR9\g(
bStop = true; :H&G}T(#
} a>rDJw:
&W c$VDC
!|j|rYi-
} E m^Dg9
hgzNEx%^q
qozvNJm)
/* y. 1F@w|
**FileAccess.java 2i;ox*SfpU
*//文件访问(定位，写) cD=IFOB*GD
package NetFox; NUJ $)qNA
import java.io.*; ly35n`
aC%Q.+-t
Jgg<u#
public class FileAccessI implements Serializable{ KU*aJl_n,
4=EA3`l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 13w(Tf
RandomAccessFile oSavedFile; 4T;<`{]
long nPos; $d!Vxm
H5&._
co1aG,>"q
public FileAccessI() throws IOException rZcSG(d`53
{ tbiM>qxB
this("",0); k#u)+e.'
} D6|-nl
0xO*8aKT
n\V7^N
public FileAccessI(String sName,long nPos) throws IOException /nuz_y\J
{ ,hT.Ok={36
oSavedFile = new RandomAccessFile(sName,"rw"); 1r_V$o$
this.nPos = nPos; ;ISe@yR;
oSavedFile.seek(nPos); k<CbI V
} mF|KjX~s
)7[#Ti
u"m(a:jQ
public synchronized int write(byte[] b,int nStart,int nLen) m(}}%VeR"z
{ 2
int n = -1; A<"<DDy
try{ {:#nrD"
oSavedFile.write(b,nStart,nLen); >iRkhA=Vg
n = nLen; &"I csxG
} Dg"szJ-
catch(IOException e) K)se$vb6
{ FpU8$o~r{
e.printStackTrace (); Q;!rN)
} m{?f,Q=u@
uwr7 .\7
mo] l_'
return n; y1T(R#
} g>;@(:e^/
;^0rY)&
4#7*B yvf
} QIlZZ
%>_6&A{K,d
z7gX@@T
/* r 1jt~0&K
**SiteInfoBean.java vJ=Q{_D=\
*/ CswKT9
package NetFox; i%i/>;DF
1JfZstT
0Ci/-3HV!
public class SiteInfoBean { {>9ED.t
|3yG
#0Y_!'j
private String sSiteURL; //Site's URL %Nvw`H
private String sFilePath; //Saved File's Path +egwZ$5I
private String sFileName; //Saved File's Name n*A1x8tn
private int nSplitter; //Count of Splited Downloading File _oCNrjt9
{\%I;2X
XD|g G
public SiteInfoBean() x: _[R{B
{//nSplitter的缺省值为5 `OWHf?t:
//default value of nSplitter is 5 y%;o
this("","","",5); q~[sKAh
} mfaU_Vo&
uf9&o#
QDV+(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {?IbbT
{ 9A} *
sSiteURL= sURL; #Xox2{~
sFilePath = sPath; FE&:?
sFileName = sName; F;8Q`$n
this.nSplitter = nSpiltter; P/|1,Sk
c$71~|-[
K)~aH
} {vCtp
oD9n5/ozo
_"L6mcI6
public String getSSiteURL() o0f`/ 6o
{ y32$b,%Xi,
return sSiteURL; &0qpgl|
} )Hmf=eoc
vno/V#e$WX
e]1Zey
public void setSSiteURL(String value) ^N|8 B?Vg
{ v[^8_y}A`
sSiteURL = value; ~"#HHaBO#
} L*[3rqER
Yg3nT:K_Y&
W_JO~P
public String getSFilePath() y^`JWs,
{ Y.]$T8
return sFilePath; X_hDU~5{wC
} !Kg']4
?\,^>4x?
usD@4!PoA
public void setSFilePath(String value) -Z$u[L [c
{ aE9Y |6
sFilePath = value; =!^ gQ0~4
} QO(F%&v++
!p/?IW+
?`rAO#1
public String getSFileName() VDbbA\
{ v#/Gxk9eX
return sFileName; @|c])
} QR'#]k;>%
w"s@q$}]8M
FZj>N(
public void setSFileName(String value) k-=LD
{ aW&)3C2-x
sFileName = value; II}M|qHaK
} iP"sw0V8
+|,4g_(j
%csrNf
public int getNSplitter() Dz6xx?
{ 3yKmuu!
return nSplitter; rFQWgWD
} n@p@@
={zTQ+7S`
3EICdC
public void setNSplitter(int nCount) ^.!jD+=I
{ hyf ;f7`o
nSplitter = nCount; 71{jedT
} A+0-pF2D
} r.\L@Y<
K8&;B)VT>
% (y{Sca
/* Bso#+v5
**Utility.java A,cXN1V
*/ qGV_oa74
package NetFox; V>`ANZ4
Fds 11 /c7
=oq8SL?bJ*
public class Utility { lt&(S)
"U-jZ5o"
j/*1zu8Y
public Utility() *b. >
{ nJ2x;';lA
g=56|G7n
i#`q<+/q
} \H@1VgmR;
c_D(%Vf5
//线程睡眠 _b~{/[s
public static void sleep(int nSecond) *c94'Tcl
{ *kl :/#
try{ $}gMJG
Thread.sleep(nSecond); k_=yb^6[U
} Ptv'.<-
catch(Exception e) T+F]hv'
{ 0\= du
e.printStackTrace (); Tn#Co$<
} rQVX^
} {}$7Bp
EyE#x_A
//日志 Z_\p8@3aH
public static void log(String sMsg) MVsFi]-
{ akzGJ3g
System.err.println(sMsg); 4\Y5RfLB_
} 0+*NHiH
pi?MAE*f
Gs,:$Im
public static void log(int sMsg) -V|"T+U
{ %'=*utOxy
System.err.println(sMsg); zXn-E
} PC#^L$cg}
} #_wq#rF
$s/E}X
>5t%_/yeB
/* 64zOEjra
**TestMethod.java 5*pzL0,Y
*/ AAevN3a#nI
package NetFox; vt|R)[,
g4[VgmhJ
!wfW0?eu
public class TestMethod { 9Ux(
GkIY2PD
N7+L@CC6T
public TestMethod() 6QX m]<
{ ///xx/weblogic60b2_win.exe `OBzOM
try{ YNEwX$)M,B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JNfL jfE)<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?BnU0R_r]
SiteFileFetch fileFetch = new SiteFileFetch(bean); (j&:
fileFetch.start(); ,yYcjs!=o
} 4N,mcV
catch(Exception e){e.printStackTrace ();} EO&Q
"]+g5G
JL1ajlm~
} WEimJrAn
^Co$X+
>X*tMhcb
public static void main(String[] args) 7MKX`S
{ hzqJ!
new TestMethod(); hxO}'`:
} bO=|utpk
} h+FM?ct6}
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