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)); ^]&{"!
} 9PK-r;2
for(int i=0;i<nEndPos.length-1;i++) \/'n[3x
{ 5C1Rub)
nEndPos = nStartPos[i+1]; u7Y< ~
} 2-!Mao"^
nEndPos[nEndPos.length-1] = nFileLength; &>.1%x@R
} #l#[\6
} q- (NZno
\N+Ta:U1P
LoE(W|nj
//启动子线程 <Cu?$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e-3pg?M
for(int i=0;i<nStartPos.length;i++) lFGxW 5
{ tkqBCKpDa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OG7v'vmY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w*%$ lhp!
nStartPos,nEndPos,i); h\*rv5\M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %L>nXj
fileSplitterFetch.start(); ~PW}sN6ppG
} iCRw}[[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '8kjTf#g<l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |!5T+H{Sj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #aY<J:Nx
nEndPos = " + nFileLength); #r)1<}_e#
// fileSplitterFetch[nPos.length-1].start(); cN}A rv
jI`To%^Y
U4l*;od
//等待子线程结束 PJ'lZu8?x
//int count = 0; Bi:wP/>v
//是否结束while循环 oEoJa:h
boolean breakWhile = false; }9udo,RWu
8pMZ~W;
`W$0T;MPF
while(!bStop) >ydb?
{ [=ak>>8
write_nPos(); 'ag6B(0Z
Utility.sleep(500); |z.GSI_!)
breakWhile = true; m4U+,|Fa
^iRwwN=d
R|J>8AL}BY
for(int i=0;i<nStartPos.length;i++) V/9"Xmv75
{ ro^6:w3O^
if(!fileSplitterFetch.bDownOver) "Xk%3\{P
{ +M O5'z
breakWhile = false; roj04|
break; p$1Rgm\
} }42qMOi#w1
} #C;zS9(]B
if(breakWhile) ]n]uN~)9
break; 7M#$: Fdb
NQiecxvt=
C:GHP$/}
//count++; wQ=yY$VP
//if(count>4) ]RXtC*
// siteStop(); g;#KBxE
} 2C33;?M
j)tCr Py
^Ii \vk
System.err.println("文件下载结束！"); 5 (21gW9
} X]pWvQ Q]
catch(Exception e){e.printStackTrace ();} -8Jl4F ,
} *- IlF]
~? FrI
+.(}u ,:8
//获得文件长度 JdUz!=I
public long getFileSize() B?lBO V4v4
{ g3~~"`2
int nFileLength = -1; :O'C:n<g
try{ Uq]EJu
URL url = new URL(siteInfoBean.getSSiteURL()); Fwx~ ~"I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZCE%38E N
httpConnection.setRequestProperty("User-Agent","NetFox"); 5 2@udp
nl-t<#z[
Q_]!an(
int responseCode=httpConnection.getResponseCode(); #S53u?JV8
if(responseCode>=400) xngeV_xc2
{ N{V5 D
processErrorCode(responseCode); bg1"v a#2
return -2; //-2 represent access is error 1;Wkt9]9
} ()nKug`.@
N?=qEX|R
?dKa;0\
String sHeader; uO_,n
eN|HJ=
`b.o&t$L
for(int i=1;;i++) %%+mWz a
{ IglJEH[+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H#|Z8^ *Ds
//Utility.log(in.readLine()); wCU&Xb$F
sHeader=httpConnection.getHeaderFieldKey(i); ),;D;LI{S
if(sHeader!=null) TvWU[=4Yk
{ Ku0H?qft(
if(sHeader.equals("Content-Length")) .kbr?N,'
{ 0/SC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *qO]v9 j
break; i{|lsd(+
} %uz|NRB=
} dI_r:xN
else W7TXI~7
break; $h,&b<-
} ;-9zMbte:
} 8!uL-_Bn
catch(IOException e){e.printStackTrace ();} T@Ss&eGT2
catch(Exception e){e.printStackTrace ();} YHO;IQ5
3b|7[7}&
o%Uu.P
Utility.log(nFileLength); L_Y9+ e
)RA\kZ"
jiwpDB&[
return nFileLength; 9 wSl,B-
} JtYYT/PB
1!>bhH}{D
.K|P&
//保存下载信息（文件指针位置） om".j
private void write_nPos() ` $.X[\*U
{ Z]x5!
try{ :kME
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y)Znb;`?a
output.writeInt(nStartPos.length); ){O1&|z-
for(int i=0;i<nStartPos.length;i++) HUU >hq9
{ Kf05<J!
// output.writeLong(nPos); &*(n<5wt
output.writeLong(fileSplitterFetch.nStartPos); 2I]]WBW#:
output.writeLong(fileSplitterFetch.nEndPos); rV8(ia
} #$rf-E5g-K
output.close(); 00`bL
} kZU"Xn
catch(IOException e){e.printStackTrace ();} rPiiC/T.`
catch(Exception e){e.printStackTrace ();} YW8K $W
} W>p\O9BG
/,1SE(
hi;WFyJTu
//读取保存的下载信息（文件指针位置） "xD}6(NL(r
private void read_nPos() DL'd&;6
{ |`_ <@b
try{ i(M(OR/4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9,S,NvSq
int nCount = input.readInt(); BGB,Gb
nStartPos = new long[nCount]; xHEVR!&c4
nEndPos = new long[nCount]; ~a'nHy1
for(int i=0;i<nStartPos.length;i++) lq>*x=<
{ eZ@Gu
nStartPos = input.readLong(); 9nng}em>.
nEndPos = input.readLong(); @DfkGm[%
} vQ:x%=]
input.close(); "C:rTIH
} $"Y3mD}?L
catch(IOException e){e.printStackTrace ();} \3%W_vU_
catch(Exception e){e.printStackTrace ();} +Fk4{p
} F3r S6_
?@Z7O.u
<KHv|)ak
private void processErrorCode(int nErrorCode) #'J~Xk
{ Qy{NS.T
System.err.println("Error Code : " + nErrorCode); ?*CRa$_I|
} sTd}cP
&q4ox71
Jq#[uX
//停止文件下载 8_"3Yb`f
public void siteStop() "NxOOLL
{ J*}VV9H
bStop = true; ijvNmn1k
for(int i=0;i<nStartPos.length;i++) r@|R-Binz
fileSplitterFetch.splitterStop(); T1lXYhAWS
^D9 /
i'M^ez)u
} nHI(V-E2:H
} `[X6#`<
//负责部分文件的抓取 rU; g0'4e
**FileSplitterFetch.java 8'3"uv
*/ bHO7*E
package NetFox; &[NVP&9&U
pt=7~+r
^Lsc`<xC
import java.io.*; ~J%R-{U9
import java.net.*; a;56k
uAp -$?
x HY+q;
public class FileSplitterFetch extends Thread { M{*kB2jr
&@=u+)^-{
TRSOO}
String sURL; //File URL h^['rmd
long nStartPos; //File Snippet Start Position '/Cg*o/
long nEndPos; //File Snippet End Position (d54C(")
int nThreadID; //Thread's ID HMF8;,<_w?
boolean bDownOver = false; //Downing is over =8O}t+U
boolean bStop = false; //Stop identical ov1Wr#s
FileAccessI fileAccessI = null; //File Access interface La\Q'0
/r>IV`n{
UV?[d:\>'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =ZG<BG_
{ $=\d1%_R|
this.sURL = sURL; grGhN q
this.nStartPos = nStart; `f%&<,i
this.nEndPos = nEnd; ?x:m;z/
nThreadID = id; d?JAUbqy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {V.Wk
} Z/xV\Ggx
IS-}:~Pi
7Aqn[1{_O
public void run() s;s0}Td_1
{ )r=9]0=
while(nStartPos < nEndPos && !bStop) "PMO
{ :b"=KQ
M#ZT2~+CT
:eSc;
try{ Pl_^nFm0
URL url = new URL(sURL); |B 9t-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y*w"J3|29
httpConnection.setRequestProperty("User-Agent","NetFox"); &xgZFSq
String sProperty = "bytes="+nStartPos+"-"; F@g17aa
httpConnection.setRequestProperty("RANGE",sProperty); [C~fBf5
Utility.log(sProperty); hl`u"?rg
Xc{ZN1 4n
Og+)J9#
InputStream input = httpConnection.getInputStream(); bdCykG-
//logResponseHead(httpConnection); x,w8r+~5
w_\nB}_
c2/"KT
byte[] b = new byte[1024]; j]AekI4I
int nRead; Z?-;.G*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [9LxhPi
{ 6Ux[,]GK
nStartPos += fileAccessI.write(b,0,nRead); '[%jjUU
//if(nThreadID == 1) ?qy*s3j'M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jl\'V
} 3]N q@t
wXz\NGW
>A<Df
Utility.log("Thread " + nThreadID + " is over!"); *E.LP1xP
bDownOver = true; +.=1^+a
//nPos = fileAccessI.write (b,0,nRead); ;;M"hI3@
} ]7*kWc2
catch(Exception e){e.printStackTrace ();} ;3mL^
} >8%M*-=p
} Ha?G=X
lHcA j{6
C(}^fJ6r
//打印回应的头信息 JT}.F!q6E
public void logResponseHead(HttpURLConnection con) xg?auje
{ }*h47t}
for(int i=1;;i++) kj-=xhJ{=
{ Mw+v"l&mU
String header=con.getHeaderFieldKey(i); _FT6]I0
if(header!=null) >d#3|;RY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pKq]X}[^c
Utility.log(header+" : "+con.getHeaderField(header)); 0Yp>+:#
else KyjyjfIwH
break; a%v>eXc
} >[EBpYi
} w#sq'vo4%
Vn^)
Zd$JW=KR]l
public void splitterStop() Z4#v~!
{ oooS s&t
bStop = true; },&h[\N{6
} 9976H\{
.8K6C]gw
~JLYhA^'+<
} #,TELzUVE
76_<xUt{
N\'TR6_,b
/* Yc|uD-y
**FileAccess.java 7_KXD#
*//文件访问(定位，写) *U_S1>0n
package NetFox; =PZWS&(L
import java.io.*; UoHd-
;I+H>$%jZ
Yh$fQ:yi\&
public class FileAccessI implements Serializable{ VtWT{y5Ec
_W}(!TKO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^zgacn
RandomAccessFile oSavedFile; ?,>5[Ha^?
long nPos; S@Iw;V
oPsK:GC`U
NCn`}QP
public FileAccessI() throws IOException "H$@b`)
{ \ADLMj`F|
this("",0); }3J=DCtS
} []gRfM]$&
2QL?]Vo
\sITwPA[z
public FileAccessI(String sName,long nPos) throws IOException t0.;nv@A0
{ ]+ZM/'X
oSavedFile = new RandomAccessFile(sName,"rw"); x9&p!&*&IT
this.nPos = nPos; W+\?~L.
oSavedFile.seek(nPos); `c9'0*-
} M$H`^Pv
cJ2PI
n[P\*S
public synchronized int write(byte[] b,int nStart,int nLen) 0<Q*7aY
{ z&F5mp@
int n = -1; +?Ez} BP
try{ m8+:=0|$
oSavedFile.write(b,nStart,nLen); 8SZK:VE@
n = nLen; `;cz;"
} :3O5ET'1
catch(IOException e) KUFz:&wK
{ G|*G9nQ
e.printStackTrace (); 7&foEJ3q
} xNIGO/uI~
#A )Ab%r8"
R5ZIC4p
return n; -=mwy
} VE$t%QT
6@YH#{~Zpv
zSXA=
} Ha)np
$w/E9EJ)3A
mX;H((
/* Cfv]VQQE
**SiteInfoBean.java p/&HUQQk
*/ P0 b4Hq3
package NetFox; ({ k7#1 h8
X}W)3v
^1 ;BiQ
public class SiteInfoBean { P,ydt
^V.'^=l
h/?6=D{
private String sSiteURL; //Site's URL SY T$3|a
private String sFilePath; //Saved File's Path ;MPKJS68@
private String sFileName; //Saved File's Name 9go))&`PJL
private int nSplitter; //Count of Splited Downloading File oj@g2H5P
CmnHh~%
F>-}*o
public SiteInfoBean() `HyF_m>\
{//nSplitter的缺省值为5 J^:n* C
//default value of nSplitter is 5 M4:s;@qZ.
this("","","",5); l!@ 1u^v2
} (O0byu}
p[qg&VKB
9!#EwPD$#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gr+Pl>C{
{ M*`hDdS
sSiteURL= sURL; 6 64q~_@B1
sFilePath = sPath; 7n&yv9"
sFileName = sName; p+Lv=e)0u
this.nSplitter = nSpiltter; 2*'ciH37
JDlBVZ!
zJCEA
} KGT3|)QN
x<F$aXOS
5v|EAjB6o
public String getSSiteURL() = F<:}Tx)C
{ taDQ65
return sSiteURL; gDC2 >nV
} $.8 H>c
C:j]43`
Yt{&rPv,
public void setSSiteURL(String value) Y;_T=L
{ -N# #w=
sSiteURL = value; J\A8qh8
} /b%Q[ Ck_
I`^YAbnb
}-nU3{1
public String getSFilePath() H~Uq?!=b
{ wOg,SMiq
return sFilePath; +t"j-}xzE
} g>n0z5&TNF
A[JM4x
iLtc HpN
public void setSFilePath(String value) #jP/k.
{ yU_9a[$V
sFilePath = value; L~&" aF/b
} ,LUTHWEo"I
k|B2@{
-oh7d$~
public String getSFileName() 8xTix1u0
{ m~>@BCn;
return sFileName; 1;&T^Gdj
} -J?~U2
D=&K&6rr
?,XC=}
public void setSFileName(String value) 9@y3IiZ"}
{ 6+PGwCS
sFileName = value; %?=)!;[
} LNiS`o\
a.,_4;'UE1
+)gB9DoK
public int getNSplitter() [{cC
{ HJ@5B"
return nSplitter; m =k%,J_
} v3-?CQb(
I%xn,u
Xw^X&Pp
public void setNSplitter(int nCount) "&-C$J5 Id
{ uvv.WbZ
nSplitter = nCount; ,Rz}=j
} t)r1"oA
} D^$OCj\
-9-fX(I
'C~9]Y].
/* j)L1H* S%
**Utility.java /s`;9)G]9
*/ j-32S!
package NetFox; 6?o>{e7n^
6mHhC?
aD|Yo
public class Utility { HcO5?{2
7cw]v"iv
KB+]eI-h
public Utility() o](.368+4
{ Euu ,mleM
`%y5\!X
SRf5W'4y
} H\+-cvl
* nCx[
//线程睡眠 9L HuS
public static void sleep(int nSecond) eP= j.$
{ tcOnM w
try{ v}P!HczmMP
Thread.sleep(nSecond); &t6Tcy
} N-QCfDao
catch(Exception e) `~nCbUUee
{ =]b9X7}
e.printStackTrace (); gZ`DT
} `bqzg
} |Fp'/~|w2d
wd+O5Lr.R
//日志 .bfST.OA
public static void log(String sMsg) H,|YLKg-|
{ ^PQM;"
System.err.println(sMsg); or.\)(m#(
} B_&^ER5j
}Vl^EAR
iZC`z }
public static void log(int sMsg) 8\_*1h40s
{ la`"$f
System.err.println(sMsg); aAcKwCGq\
} 7d9Z/J@>
} (hsZ
]]y[t|6
PbN3;c3
/* {AgBwBCE
**TestMethod.java ^A#x<J+
*/ !gJzg*{u@
package NetFox; NWnWk
U8[Qw}T P
G?ZC9w]rA
public class TestMethod { `^%@b SE(
Tk](eQsy.v
3?^NN|xg
public TestMethod() a7*COh
{ ///xx/weblogic60b2_win.exe Z@oKz:U
try{ t= *Jg/$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Hz?,#>{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Bac|;+L~L
SiteFileFetch fileFetch = new SiteFileFetch(bean); T 9MzUV&
fileFetch.start(); UM\}aq=,
} JZw^W{
catch(Exception e){e.printStackTrace ();} DaCblX
[yF^IlSs
:`5;nl63
} |0]YA
dk:xnX%
$eMK{:$O
public static void main(String[] args) eI?HwP{m
{ 5p{25N_t
new TestMethod(); N'a?wBBR
} tvCcyD%w
} -R8/`M8GbD
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