http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); k%2Rv4)hU
} "79"SSfOc
for(int i=0;i<nEndPos.length-1;i++) t IO 'ky
{ /+zzZnLl-M
nEndPos = nStartPos[i+1]; WIkr0k
} hsEQ6
nEndPos[nEndPos.length-1] = nFileLength; #!RO,{FT
} ,,o5hD0V9
} dSq3V#Q
Uh=@8v
1?hx/02
//启动子线程 Ubf@"B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d@IV@'Q7u
for(int i=0;i<nStartPos.length;i++) ;fl3'.S[
{ "o6a{KY(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]46#u=y~3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F!pgec%]'
nStartPos,nEndPos,i); ccm(r~lhJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8 bpYop7 L
fileSplitterFetch.start(); `%nj$-W:
} 5ON\Ve_H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dg~L"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Lj#K^c Ee
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ir\f_>7
nEndPos = " + nFileLength); Pt^SlX^MM
// fileSplitterFetch[nPos.length-1].start(); 3wf&,4`EX
1Bhd-
t~(|2nTO5
//等待子线程结束 uFl19
//int count = 0; Yp(F}<f?
//是否结束while循环 Yv ZcG3@c3
boolean breakWhile = false; ^oYudb^%
&8R!`uh1
ey ;94n:<
while(!bStop) 5?M d
{ w0(1o_F7.
write_nPos(); 'j27.Ry.
Utility.sleep(500); Htn''adg5
breakWhile = true; &w7Ev21
6X`i*T$.
r< ~pSj
for(int i=0;i<nStartPos.length;i++) 'En|-M5
{ h =E)5&Z
if(!fileSplitterFetch.bDownOver) eemw I
{ 4/:}K>S_
breakWhile = false; uW4wTAk;qh
break; H)VzPe#{
} S#{gCc
} @})]4H
if(breakWhile) s.qo/o\b
break; @eOD+h'
yuA+YZ
|18h p
//count++; yNc"E
//if(count>4) pS6p}S=1]
// siteStop(); :Y)jf
} ;FfDi*S7
BWG*UjP M
+p"}F PIK
System.err.println("文件下载结束！"); ,C97|6rC
} 97 eEqI$#
catch(Exception e){e.printStackTrace ();} MFzJ 8^.1R
} 6#gS`X23Y
:plN<8
pEp`Z,p
//获得文件长度 Ef~Ar@4fA
public long getFileSize() 56`Tna,t
{ HY!R|
int nFileLength = -1; u(W+hdTap=
try{ ~OSgpM#O!T
URL url = new URL(siteInfoBean.getSSiteURL()); X"Ca
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hI>vz"J
httpConnection.setRequestProperty("User-Agent","NetFox"); Vl\8*!OL%
cN3!wE
ms%RNxU4:
int responseCode=httpConnection.getResponseCode(); /?*GJN#
if(responseCode>=400) 2&o jQhe
{ -g\;B
processErrorCode(responseCode); >K;DBy*
return -2; //-2 represent access is error >h3m/aeNC
} Mv?$zV"`#
9,c_(%C
?[VL 2dP0
String sHeader; L'L[Vpx
{16]8-pe
j/p1/sJ[y
for(int i=1;;i++) {3`cSm6c
{ N> jQe
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /nWBol,
//Utility.log(in.readLine()); F?+\J =LT
sHeader=httpConnection.getHeaderFieldKey(i); {|{;:_.>
if(sHeader!=null) "K c/Cs2[
{ Rl{e<>O\^
if(sHeader.equals("Content-Length")) lx\9Y8
{ 5RsO^2V:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >r\q6f#J4
break; 4&kC8 [r
} )lZoXt_3
} g^: &Dh
else l=PZlH y1G
break; [nASMKK0
} U!i1~)s
} J!\oH%FJp
catch(IOException e){e.printStackTrace ();} x/dyb.
catch(Exception e){e.printStackTrace ();} "IN[(
("KtJ
1I?`3N
Utility.log(nFileLength); Jo''yrJpB
?[<#>,W
f]48-X,^6
return nFileLength; PH$C."Vv
} @1N.;]|
V}X>~ '%
!nU|3S[b
//保存下载信息（文件指针位置） *7o@HBbF
private void write_nPos() N 9W,p2
{ bH.SUd)
try{ m+Kl
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z 4QL&?U
output.writeInt(nStartPos.length); m6uFmU*<M}
for(int i=0;i<nStartPos.length;i++) G=/^]E
{ ^r~O*
// output.writeLong(nPos); Cto>~pV
output.writeLong(fileSplitterFetch.nStartPos); *,|x p
output.writeLong(fileSplitterFetch.nEndPos); E#R1
} f?$yxMw:@
output.close(); X-*LA*xbN
} :nOI|\rC
catch(IOException e){e.printStackTrace ();} y* :C~
catch(Exception e){e.printStackTrace ();} {)(Mkm+d
} <JIqkGeAi
6 2#@Y-5
U+R9bn
//读取保存的下载信息（文件指针位置） xX|f{)<
private void read_nPos() EU7nS3K)O~
{ Z((e-T#,
try{ /dO*t4$@?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gO{$p q}
int nCount = input.readInt(); Y-lwS-Ii
nStartPos = new long[nCount]; U1`pY:P
nEndPos = new long[nCount]; aJ@lT&.
for(int i=0;i<nStartPos.length;i++) osc A\r
{ %(|-+cLW+
nStartPos = input.readLong(); `=S%!akj
nEndPos = input.readLong(); |8tKN"QG
} 2}XxRJ0
input.close(); T"t.t%(8
} Y9I|s{~
catch(IOException e){e.printStackTrace ();} k!bG![Ie|
catch(Exception e){e.printStackTrace ();} +@c$n`>)
} 39MOqVc
p2U6B
Kn1T2WSAg
private void processErrorCode(int nErrorCode) p()LQT!
{ X#Ob^E%J
System.err.println("Error Code : " + nErrorCode); kZhd^H.
} LcT;7yv
wwv+s~(0
L)8%*X
//停止文件下载 8H1&=)M=
public void siteStop() nBLb1T
{ re,}}'
bStop = true; aK_k'4YTm
for(int i=0;i<nStartPos.length;i++) I2krxLPd
fileSplitterFetch.splitterStop(); byTHSRt
q&}+O
VoQhzp6&
} mN>(n+ly
} JNT|h zV
//负责部分文件的抓取 ;.<HpDfG_
**FileSplitterFetch.java C9_[ke[1D
*/ |Qb@.
package NetFox; CMyz!jZ3
Q5l+-
]omBq<ox'Y
import java.io.*; j<6+p r
import java.net.*; )||CU]"b?
LM 1Vsh<
U(Bmffn4Z
public class FileSplitterFetch extends Thread { [>U2!4=$M
:`lP+y?a1
kem(U{m
String sURL; //File URL B&BL<X r
long nStartPos; //File Snippet Start Position FUZuS!sJ
long nEndPos; //File Snippet End Position gX$gUB) x
int nThreadID; //Thread's ID ,b5vnW\
boolean bDownOver = false; //Downing is over gzy|K%K
boolean bStop = false; //Stop identical Gm3`/!r
FileAccessI fileAccessI = null; //File Access interface mB6%. "
uHRxV"@}[1
LPZ\T}<l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g>#}(u!PH
{ 1 .[OS
this.sURL = sURL; Oqt{ uTI~
this.nStartPos = nStart; .,U4 ATO
this.nEndPos = nEnd; c4r9k-w0E
nThreadID = id; U_.}V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |/$954Hr#<
} ori[[~OyB
_ b</ ::Tp
.6I'V3:Kg
public void run() Eau V
{ ITEf Q@#jU
while(nStartPos < nEndPos && !bStop) p:eaZ
{ Y*O Bky
CJwzjH
(d*||"
try{ d2)]6)z6
URL url = new URL(sURL); ?AQA>D#W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4Ssy (gt
httpConnection.setRequestProperty("User-Agent","NetFox"); ,H<nNBv3M
String sProperty = "bytes="+nStartPos+"-"; ue4{h
httpConnection.setRequestProperty("RANGE",sProperty); "`%UC#
Utility.log(sProperty); g!r)yzK
DRTT3;,N
$!_}d
InputStream input = httpConnection.getInputStream(); ~*+evAP
//logResponseHead(httpConnection); AxF$7J(
A:(qF.Tm
fF=tT C
byte[] b = new byte[1024]; p,uM)LD
int nRead; 1CM8P3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h|ib*%P_
{ #`l&HV
nStartPos += fileAccessI.write(b,0,nRead); 2+pXtP@O
//if(nThreadID == 1) 4d}n0b\d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hJw]hVYa
} ~"4Cz27
=<zlg~i
-/*VR$c
Utility.log("Thread " + nThreadID + " is over!"); "Vp:Sq9y
bDownOver = true; =NnG[#n%
//nPos = fileAccessI.write (b,0,nRead); :Z_abKt
} $ 9E"{6;@
catch(Exception e){e.printStackTrace ();} C7}iwklcsa
} {a9.0N:4
} z(2G"}
<1:I[b
5~(nHCf>
//打印回应的头信息 $(08!U
public void logResponseHead(HttpURLConnection con) 8YgRJQZ!
{ ?P#\CW
for(int i=1;;i++) ;TwqZw[.
{ F[F NtZ
String header=con.getHeaderFieldKey(i); H`Zg-j`
if(header!=null) ~DB:/VSmu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3/(eK%d4Xb
Utility.log(header+" : "+con.getHeaderField(header)); jZvIqR/
else 322-'S3<
break; zzh7 "M3Qn
} %\)AT"
} ~XvMiWuo
O`N,aYo
f9IqcCSW
public void splitterStop() /rK/l
{ qF`]}7"^
bStop = true; LcNI$g;}Yf
} +Mn(s36f2
02(Ob
U7,.L
} I?%#`Rvu
fi&>;0?7
+>c%I&h}`
/* -7J~^m2x
**FileAccess.java -$@'@U
*//文件访问(定位，写) )oM% N
package NetFox; <$#^)]Ts
import java.io.*; 5>=4$!`
pE0@m-p
e ]2GAJLI
public class FileAccessI implements Serializable{ y`/:E<fVk
Eq8:[o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XB:E<I'q!3
RandomAccessFile oSavedFile; N f}ZG
long nPos; NpbZt;%t
ygK,t*T20
Z]5xy_La
public FileAccessI() throws IOException XXD4T9Wy
{ ,Hp7`I>/
this("",0); \`-xxhb?e
} 4CS$%Cu\?w
a'*~E?b
e. E$Ej]w
public FileAccessI(String sName,long nPos) throws IOException P$@:T[}v
{ 5B3sRF}
oSavedFile = new RandomAccessFile(sName,"rw"); 5CH8;sMK
this.nPos = nPos; xsvJjs;=
oSavedFile.seek(nPos); {"rL3Lk
} c s:E^
>J:liB|(
Mi}k>5VT
public synchronized int write(byte[] b,int nStart,int nLen) bJeF1LjS
{ KsqS{VVCh
int n = -1; ItZ*$I1<
try{ k? ,/om1
oSavedFile.write(b,nStart,nLen); s>{\^T7y
n = nLen; F9r|EU#;
} )L_@l5l
catch(IOException e) !|mzu1S
{ PMQlJ&
e.printStackTrace (); e Dpt1
} { / ,?3
ITz+O=I4R]
{Z>Mnw"R
return n; %P C[-(Q
} `@So6%3Y|
"DX2Mu=
m;U_oxb
} P\@efq@!
8RS@YO
7b8y
/* 8}Q2!,9Q
**SiteInfoBean.java FU)=+m
*/ I:;umyRH
package NetFox; *-E'$
3A.lS+P1
m+x$LkP
public class SiteInfoBean { Sj viH
p]7IoO -@
R^INl@(O
private String sSiteURL; //Site's URL 0aJcX)
private String sFilePath; //Saved File's Path f`[E^zj
private String sFileName; //Saved File's Name _auFt"n
private int nSplitter; //Count of Splited Downloading File h"f_T [
1=PTiDMJ<*
&#!1 Y[e^
public SiteInfoBean() #1WCSLvtV
{//nSplitter的缺省值为5 qTGi9OP6/
//default value of nSplitter is 5 YhP+{Y8t
this("","","",5); q RRvZhf
} b&9~F6aM
a.a ,_
xrv0%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VL|Z+3L
{ mrig5{
sSiteURL= sURL; jVqpokWH
sFilePath = sPath; +fQJ#?N2n
sFileName = sName; \p^'[B(O77
this.nSplitter = nSpiltter; FB %-$
B`)bo}h
dk0} q6~
} 2q*wYuc
fm!\**Q1
bRr3:"=sE
public String getSSiteURL() `A-
{ Y8N+v+V/
return sSiteURL; sD|}?7
} NCgKWyRR
TIK'A<
*U`R<mV\
public void setSSiteURL(String value) )_6W@s
{ Kq(JHB+
sSiteURL = value; ex66GJQe1
} FrE#l.)?!
8\jsGN.$JZ
o'8nQ Tao
public String getSFilePath() D ,[yx='
{ LjIkZ'HuF
return sFilePath; T`9nY!
} kdaq_O:s
Zay%QNsb
Z;njSw%:
public void setSFilePath(String value) 9!.S9[[N
{ 0%)T]SDS
sFilePath = value; ~YByyJG
} E()%IC/R
^]Z@H/]H
&(e5*Q
public String getSFileName() C~C`K%7
{ lQy-&d|=#^
return sFileName; ) $0>L5d:
} !Uv>>MCr
|dDKO
=^\?{oV
public void setSFileName(String value) f>|<5zm#<
{ H!>>|6OPF
sFileName = value; 6YV"H
} 5"X@<;H%
{R_ <m$
z7+>G/o
public int getNSplitter() )PW|RW
{ IW-|"5?9'
return nSplitter; Kr;=4xg=
} |o'r?"
L27WDm^)
$?dQ^]<,
public void setNSplitter(int nCount) UtQCTNjC{
{ IAmZ_2
nSplitter = nCount; _O;4>
} upX@8WxR
} o\; hF3
dZI["FeO&d
YBR)S_C$_
/* Ob}XeN(L3
**Utility.java +S`cUn7
*/ ),[@NK&=
package NetFox; \CVHtV
(E,Ibz2G:e
adAdX;@e`
public class Utility { pLys%1hg
vU]n0)<KB
Nh}u]<B
public Utility() h+A+>kC5
{ !2^~ar{2
&Yc'X+'4
=LKM)d=1
} +l.LwA
Pai8r%Zfu
//线程睡眠 #Sx
public static void sleep(int nSecond) O:GAS [O`
{ V|[NL4
try{ [HUK 9hG
Thread.sleep(nSecond); xSNGf@1b
} 3,X8 5`v^
catch(Exception e) qxsHhyB_n;
{ x5V))~Ou
e.printStackTrace (); VJFFH\!`
} ?Zsh\^k.g
} R!lug;u#
nc\2A>f`
//日志 aM(#J7;
public static void log(String sMsg) R/*"N'nH-%
{ I%GQ3D"=
System.err.println(sMsg); TA2ETvz^
} pek=!nZ
OK8Ho"
RyG6_G}
public static void log(int sMsg) O`"~AY&
{ YD;d*E%t
System.err.println(sMsg); iyd$_CJz
} X!mJUDzh]
} LHXR7Fjc
VJT /9O)Z|
Xt$P!~Lu
/* 4Orq;8!BW
**TestMethod.java x[Hx.G}5+
*/ TI/RJF b
package NetFox; o3GkTn O
6M_:D
5J|S6x\
public class TestMethod { P=KhR&gwV~
~cfXEjE6
D7JrGaF{
public TestMethod() jZPGUoRLg
{ ///xx/weblogic60b2_win.exe i*m;kWu,
try{ ~:o$}`mW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wytMoG\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I`rN+c:
SiteFileFetch fileFetch = new SiteFileFetch(bean); cNxxX!P/
fileFetch.start(); 6 U[VoUU
} {*TB }Xsr,
catch(Exception e){e.printStackTrace ();} r|DIf28MIq
9d-'%Q>+
+xO3<u
} fCF.P"{W"
E;x-O)(&
3nc\6v%
public static void main(String[] args) v<g=uEpN
{ KsE$^`
new TestMethod(); B5vLV@>]
} o:W*#dt
} f$kbb6juL
点击下载更多相关资料