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)); 7 W{~f?Sh
} x<s|vgl|
for(int i=0;i<nEndPos.length-1;i++) n$YE !D'
{ -E]Sk&4Gj
nEndPos = nStartPos[i+1]; /VO^5Dnb
} 5qRc4d'
nEndPos[nEndPos.length-1] = nFileLength; <BPRV> 0X
} ]~8v^A7u
} ]`d2_mu
88g47>{X
(]XbPW
//启动子线程 ?q!FG(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b=1%pX_
for(int i=0;i<nStartPos.length;i++) [O_^MA,z
{ <s}|ZnGE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sT`^ljp4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7)J6/('
nStartPos,nEndPos,i); q^*6C[G B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ej52AK7
fileSplitterFetch.start(); <0 uOq
} Me/\z^pF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^=0$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C(o.Cy6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ],[)uTZc
nEndPos = " + nFileLength); G52Z)^
// fileSplitterFetch[nPos.length-1].start(); MCU9O
[N:BM% FQ
<GF@L
//等待子线程结束 k|FSz#Y
//int count = 0; >'`Sf ?+|
//是否结束while循环 .GCR!V
boolean breakWhile = false; _faJB@a_
:#$F)]y'\
[M:S`{SbY
while(!bStop) ooE{V*Ie
{ y94kX:q
write_nPos(); eOnTW4
Utility.sleep(500); \H4U8)l
breakWhile = true; >SDpuG&>
l}}UFEA^
vT7g<
for(int i=0;i<nStartPos.length;i++) [w+Q^\%bN
{ EzwF`3RjK
if(!fileSplitterFetch.bDownOver) &s_}u%iC
{ 72% {Wh/
breakWhile = false; eq7C]i rH
break; W>UjUq);
} ">0 /8]l
} +._f.BRmX.
if(breakWhile) $::51#^Wg
break; y0lLFe~
SlM>";C\
)E_!rR
//count++; 3<yCe%I:
//if(count>4) %,h!: Ec^c
// siteStop(); A89Y;_4y
} :Fq2x_IUE
ei(|5h
R#rh
System.err.println("文件下载结束！"); \Gv-sA
} /<Gyg7o0
catch(Exception e){e.printStackTrace ();} 4j2~"K
} UEk|8yq
7UY('Q[
pyGFDB5_P
//获得文件长度 nau~i1
public long getFileSize() 8yNRxiW:
{ 3ytx"=B%
int nFileLength = -1; %!1@aL]pQ
try{ ]M02>=1
URL url = new URL(siteInfoBean.getSSiteURL()); )[F46?$vrk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jLpgWt`8)E
httpConnection.setRequestProperty("User-Agent","NetFox"); xUV_2n+
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U!3uaz'
int responseCode=httpConnection.getResponseCode(); &^"s=g.
if(responseCode>=400) jKe$&.q@
{ >:(6{}b
processErrorCode(responseCode); =Td#2V;0
return -2; //-2 represent access is error #h}IUR
} OpbszSl"y
Jc9@VxWY
iGpK\oH
String sHeader; W` 6"!V
y81#UD9[
6tCV{pgm
for(int i=1;;i++) xV }:M
{ Wl@0TUK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S S7D1
//Utility.log(in.readLine()); x|P<F2L
sHeader=httpConnection.getHeaderFieldKey(i); |sDG>Zq?
if(sHeader!=null) n:{-Vvt
{ .je~qo)
if(sHeader.equals("Content-Length")) 5+#?7J1
{ 10a=YG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =2GP^vh
break; T% jjs
} e%5'(V-y,
} \ZmFH8=|f
else S0X.8Bq
break; ^$T!@+:
} .F=<r-0
} MC[`<W)u
catch(IOException e){e.printStackTrace ();} H-PW(
catch(Exception e){e.printStackTrace ();} wjw<@A9
l=<F1Lz
R oF
Utility.log(nFileLength); v{\n^|=])
Es ZnGuY
iLI.e rm
return nFileLength; 1GyAQHx,
} K%.YNVHHC
xOX*=Wv
(PE8H~d
//保存下载信息（文件指针位置） V8|q"UX
private void write_nPos() 3z{5c
{ &,6y(-
try{ t8a@L(J$
output = new DataOutputStream(new FileOutputStream(tmpFile)); P*nT\B
output.writeInt(nStartPos.length); @pEO@bbg>
for(int i=0;i<nStartPos.length;i++) EzeDShN=J
{ 9cx!N,R t
// output.writeLong(nPos); GwU>o:g"
output.writeLong(fileSplitterFetch.nStartPos); vb80J<4
output.writeLong(fileSplitterFetch.nEndPos); b*F :l#
} AU${0#WV_
output.close(); /oixtO)
} C$Hl`>?$
catch(IOException e){e.printStackTrace ();} F"HI>t)>
catch(Exception e){e.printStackTrace ();} 0'`8HP
} iMY0xf8l
u" NIG
)b:~kuHi
//读取保存的下载信息（文件指针位置） bl!f5ROS(
private void read_nPos() GhfUCW%
{ u3v6$CD?
try{ `mHOgS>|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z ^9{Qq
int nCount = input.readInt(); DRFuvU+e
nStartPos = new long[nCount]; JCU3\39}
nEndPos = new long[nCount]; "gl:4|i'
for(int i=0;i<nStartPos.length;i++) GwIfGixqH
{ JWm^RQ
nStartPos = input.readLong(); @{$Cv"6769
nEndPos = input.readLong(); r>:7${pF
} M&BM,~
input.close(); ~jCpL@rS
} 8BoT%kVeJv
catch(IOException e){e.printStackTrace ();} p'w"V6k('~
catch(Exception e){e.printStackTrace ();} U!-+v:SF
} "3>*i!i
?H86Wbz
%F]9^C+
private void processErrorCode(int nErrorCode) :,z3:PL
{ <[B[
System.err.println("Error Code : " + nErrorCode); tP^mq>
} p31rhe
$CYpO}u#
Wj{Rp{}3
//停止文件下载 i,b7Ft:F&
public void siteStop() pNf9
{ [+cnx21{
bStop = true; ~FCSq:_
for(int i=0;i<nStartPos.length;i++) ZT6X4 Z
fileSplitterFetch.splitterStop(); s2v#evI`+
sq(063l
en#g<on
} )PoI~km
} Wv*BwiQ
//负责部分文件的抓取 $^D(%
**FileSplitterFetch.java (>5VS
*/ yLIj4bf
package NetFox; :AcNb
VOK$;s'9}
YU0HySP:
import java.io.*; '<W,-i
import java.net.*; HF=C8ZtlL
1*,~1!>
EKS<s82hF&
public class FileSplitterFetch extends Thread { WyJfF=<
A=[f>8
96E7hp !:
String sURL; //File URL o/[yA3^
long nStartPos; //File Snippet Start Position wj5s5dH
long nEndPos; //File Snippet End Position T]Td4T!
int nThreadID; //Thread's ID qsRfG~Cg
boolean bDownOver = false; //Downing is over .q[sk
boolean bStop = false; //Stop identical pz6- hi7
FileAccessI fileAccessI = null; //File Access interface =|&"/$+s
A_*Lo6uII
9n\#s~,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -/7=\kao%
{ oYm{I ~"
this.sURL = sURL; \V- Y,!~5
this.nStartPos = nStart; it|:P
this.nEndPos = nEnd; e^Wv*OD'
nThreadID = id; .O-DVW Cm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9X&qdA/q
} e`2R{H
-V_S4|>
SR8Kzk{
public void run() #2'&=?J1r
{ E=~WQ13Q
while(nStartPos < nEndPos && !bStop) 4k?JxA)
{ `lh?Z3W
K]*ERAfM%m
!J(,M)p!
try{ L , Fso./y
URL url = new URL(sURL); 2u H\8A+'f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [_G0kiI}W"
httpConnection.setRequestProperty("User-Agent","NetFox"); VP[!ji9P
String sProperty = "bytes="+nStartPos+"-"; 5$Q`P',*Ua
httpConnection.setRequestProperty("RANGE",sProperty); %c2i.E/G
Utility.log(sProperty); "/-v 9
VRP.tD
[>9"RzEl
InputStream input = httpConnection.getInputStream(); !4.^@^L|\
//logResponseHead(httpConnection); "8dnFrE
(s*Uz3sq
5)NfZN#&
byte[] b = new byte[1024]; y]r~v
int nRead; <).qe Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'R5l =Wf
{ nln[V$
nStartPos += fileAccessI.write(b,0,nRead); HZ4 ^T7G
//if(nThreadID == 1) I[IQFka}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 959jp85
} 0(f;am0y
!e"m*S.(6{
ZoReyY2
Utility.log("Thread " + nThreadID + " is over!"); PCnJ2
bDownOver = true; 3evfX[V#
//nPos = fileAccessI.write (b,0,nRead); \gv x)S11
} wTbIS~!gF
catch(Exception e){e.printStackTrace ();} VOOThdR
} *!s?hHv
} OWfj<#}t+
`;2`H, G'
uQ+$HzxX
//打印回应的头信息 leJd){
public void logResponseHead(HttpURLConnection con) ]h$TgX
{ p5t#d)
for(int i=1;;i++) X_8NW,
{ /UyE- "S
String header=con.getHeaderFieldKey(i); h;[Ncj]
if(header!=null) T=Q{K|JE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $oj<yH<i
Utility.log(header+" : "+con.getHeaderField(header)); D];([:+4
else L(S.
break; ^P`'qfZ
} =B%e0M
} Jl,x~d
XKIJ6M~5k
8?pZZtad
public void splitterStop() hIr^"kVK
{ ~Nh7C b_
bStop = true; rrRC5h
} "evV/Fg(
&"n9,$
;KN@v5`p
} 3_/d=ZI\
E zUjt)wF
ka[NYW{.
/* P*sCrGO%
**FileAccess.java Sd11ZC6
*//文件访问(定位，写) sxa (
package NetFox; {Vu:yh\<
import java.io.*; t4uxon
8#B;nyGD1I
mq9&To!
public class FileAccessI implements Serializable{ n8,/olqwW
QV1%Zou
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [}3Y1t{G
RandomAccessFile oSavedFile; ^Tmmx_Xw
long nPos; 6nhB1Aei
8;rS"!qM
{4*%\?c,n
public FileAccessI() throws IOException Pw.+DA
{ /RJSkF+!
this("",0); \ziF(xTvqG
} JwcP[w2
!1R
<{uIB;P
public FileAccessI(String sName,long nPos) throws IOException mj~CCokF{?
{ 5Px_vtqP
oSavedFile = new RandomAccessFile(sName,"rw"); TUr}p aw_
this.nPos = nPos; yRDLg c
oSavedFile.seek(nPos); VvKH]>*
} `#U6`[[
K)OlCpHc
9hU@VPB~
public synchronized int write(byte[] b,int nStart,int nLen) =h{2!Ah7 X
{ H\vO0 <X
int n = -1; 5H2|:GzUc
try{ )G&OX
oSavedFile.write(b,nStart,nLen); V"73^
n = nLen; *^ BE1-
} yD"sYT
catch(IOException e) 1<5yG7SZ
{ f^ qQ5N
e.printStackTrace (); =c'LG
} A:Z:&(NtE:
K.~U%v}
5N/;'ySAE_
return n; m\=u/Zip
} gE~31:a^
!5-[kG&
XMdYted
} 6D<A@DR9J
!$HWUxM;p
&D#v0!e~x
/* `x{gF8GV
**SiteInfoBean.java :1Cc~+]w(u
*/ 6G],t)<A'-
package NetFox; oGZ9@Y)(T
DS fKUx&
\ZB;K~BV&
public class SiteInfoBean { pV8,b
sEa:p:!
H Vy^^$
private String sSiteURL; //Site's URL 0a5P@;"a
private String sFilePath; //Saved File's Path '`u1,h
private String sFileName; //Saved File's Name IcZ'KV
private int nSplitter; //Count of Splited Downloading File NR5A"_'
+nuQC{^>
V<7Gd8rDMM
public SiteInfoBean() y:L|]p}huE
{//nSplitter的缺省值为5 5I14"Qf
//default value of nSplitter is 5 $.kYAsZts
this("","","",5); gFH_^~7i8p
} N>_7Ltw/
<4Fd~
B$G8,3,:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P?F:x=@'|
{ Zl)|x%z
sSiteURL= sURL; 1N&U{#4
sFilePath = sPath; U&NOf;h$
sFileName = sName; Jz6PqU|=
this.nSplitter = nSpiltter; `}bUf epMJ
?l/rg6mbI'
<~3 aaO
} Cnolka"
Jc+U$h4
3^\y>
public String getSSiteURL() Y'P8`$
{ !Zrvko
return sSiteURL; \ gN) GR
} c?d#Bj ?
TJ<PT
1NTe@r!y
public void setSSiteURL(String value) U7W ct %
{ 6!$S1z#wM
sSiteURL = value; M\%{!Wzo8
} ocMf}"
,#A,+!4
) E\pQ5&
public String getSFilePath() @l8?\^N
{ 1#V0g Q
return sFilePath; B.|vmq,u
} d3\8BKp
wcOAyo5(n
$2.DZ
public void setSFilePath(String value) 3Rm$
{ AYi$LsLhO
sFilePath = value; "YBA$ef$
} _C4^J
IO+z:D{
/c7j@=0
public String getSFileName() E*%{Nn
{ k}/: xN"
return sFileName; Pzqgg43Xf
} Z`W.(gua
;KhYh S(q
-nW{$&5AF
public void setSFileName(String value) lbPxZ'YO#
{ 3"".kf,O5e
sFileName = value; HOw hl
} _eF*8 /z
~ 0[K%]]
8WH>
public int getNSplitter() KQqlM
{ Zj JD@,j
return nSplitter; %F7aFvl*
} ^ey\ c1K
WM#!X!Vo
AIeYy-f
public void setNSplitter(int nCount) Ub"\LUu
{ 8c~H![2u
nSplitter = nCount; @EQ{lGpU3
} |LQmdgVr$
} 9.R_=
`>*P(yIN
M_e!s}F
/* IoX(Pa
**Utility.java L/ZZe5I
*/ #Ky0` n
package NetFox; F,D&
V$@2:@8mo
T&c[m!}X|t
public class Utility { 7+c@pEU]
r'8e"pTi
3S,pd0;
public Utility() 5xiYCOy
{ y`N1I
Z` Aiw."|
(*EN!-/
} H$;\TG@,
ZpdM[\Q-
//线程睡眠 =}L[/RL
public static void sleep(int nSecond) z/TRqD
{ BP7_o63/G
try{ A=,m
Thread.sleep(nSecond); YP6+o#==
} V6!oe^a7'
catch(Exception e) #qPk,a
{ .B)v "Sw#
e.printStackTrace (); ":Q70*xSm
} us]ah~U6A
} xj}N;FWo
%!q(zql
//日志 Yc %eTh
public static void log(String sMsg) 4M:oa#gh@
{ a}fW3+>
System.err.println(sMsg); <sTaXaq?
} ;9^B# aTM
0e:aeLh
6(z.(eT
public static void log(int sMsg) ^a(q7ZfY
{ u]}Xq{ZN
System.err.println(sMsg); 4uv }6&R
} &O'yhAP] j
} iCHZ{<k
#*~ (
d ][E;$
/* IL~yJx_11
**TestMethod.java d<whb2l
*/ V +hV&|=
package NetFox; DQ~@=%?ni
.v;Npm2
.-r 1.'.A
public class TestMethod { }vL[N~5\
=?}'\ >G "
-H]svOX
public TestMethod() $Fn# b|e
{ ///xx/weblogic60b2_win.exe H95VU"
try{ hIdGQKr>V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,Pl[SMt!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A(C3kISM
SiteFileFetch fileFetch = new SiteFileFetch(bean); |.,yM|
fileFetch.start(); Fb_~{q
} isaT0__8
catch(Exception e){e.printStackTrace ();} :ortyCB:H
2Zl65
!~RD>N&n
} bi_R.sfK&
J/mLB7^R
9|go`^*.
public static void main(String[] args) /E*P0y~KTW
{ xv)7-jlx
new TestMethod(); 5?Bi+fg
} fpzTv3D=I
} L'c4i[~s
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