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)); k(!#^Mlz[
} kC6J@t)
for(int i=0;i<nEndPos.length-1;i++) BPtU]Bv-
{ ,}F{V>dhn
nEndPos = nStartPos[i+1]; enE8T3
} /id(atiF^
nEndPos[nEndPos.length-1] = nFileLength; 6imDA]5N&
} ]#KZ W)M
} e*=N\$
7hY~
e&#qj^
//启动子线程 `TBau:ElI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LQ373 j-
for(int i=0;i<nStartPos.length;i++) ~O&3OL:L
{ !/sXG\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g/J ^YT!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q(>89*b&
nStartPos,nEndPos,i); XF'K dz>p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BPwFcT)i!(
fileSplitterFetch.start(); 6xvyhg#B
} Em%"]B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;y Wfb|!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ){ArZjG>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [$ vAjP
nEndPos = " + nFileLength); ESL(Mf'
// fileSplitterFetch[nPos.length-1].start(); UcKpid
I~gU3(
7J.alV4`/
//等待子线程结束 hZU@35~BN
//int count = 0; =T|Z[/fto
//是否结束while循环 H<Ed"-n$I<
boolean breakWhile = false; k[&+Iy
]|@RWzA
wk'|gI[W
while(!bStop) mtvfG
{ 58ev (f
write_nPos(); "O!J6
Utility.sleep(500); ^dM,K p
breakWhile = true; zkA"2dh
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z%<Z#5_N
for(int i=0;i<nStartPos.length;i++) +Gg6h=u
{ eZJrV}V
if(!fileSplitterFetch.bDownOver) 7?Q<kB=f
{ .r[kNh@ b%
breakWhile = false; 8fY1~\G:\
break; 049E#[<Q"
} \,+act"v
} *$0uAN
if(breakWhile) C{H:-"\J9
break; ^0Cr-
aq@/sMn
n3da@ClBt
//count++; 'P3CgpF<Z2
//if(count>4) oQ{(7.e7)
// siteStop(); 0sD"Hu
} [yF>W$Bn%
\'q 9,tP
"u@)
System.err.println("文件下载结束！"); 82O#Fe q
} /4}{SE
catch(Exception e){e.printStackTrace ();} 07:CcT
} xxpvVb)mF
%3M1zZY
H.3+5po
//获得文件长度 ""|vhgP
public long getFileSize() 8vjaQ5
{ ZaIlo5
int nFileLength = -1; Y_ b;1RN
try{ Bb_R~1 l
URL url = new URL(siteInfoBean.getSSiteURL()); -|"W|K?nq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &-mPj82R
httpConnection.setRequestProperty("User-Agent","NetFox"); fRS)YE@a:
Q& j:ai*
IxNY%&* `
int responseCode=httpConnection.getResponseCode(); n}Pz:
if(responseCode>=400) h&|q>M3
{ ,HO~NqmB4
processErrorCode(responseCode); ;nW#Dn9
return -2; //-2 represent access is error (U#4j 6Q
} Q ;V `
$d? N("L
Lf`LFPKb
String sHeader; 35|F?Jx.r
Ou/JN+2A
//9Ro"
for(int i=1;;i++) EdbLAagI6
{ ;4tmnC>OnA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E2+x?Sc+
//Utility.log(in.readLine()); ^@5#jS2
sHeader=httpConnection.getHeaderFieldKey(i); I CCmE#n
if(sHeader!=null) E`]lr[
{ KV v0bE
if(sHeader.equals("Content-Length")) c'ExZ)RJ
{ J\VG/)E
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lv\C(^mGq
break; nK=-SQ
} t6V@00M@
} k`[ L
else A2.[P==
break; g).k+
} Lx6C fR
} p^S]O\;M7
catch(IOException e){e.printStackTrace ();} A14}
catch(Exception e){e.printStackTrace ();} Hyx%FN=
Pp.qDkT
R-CFF
Utility.log(nFileLength); Ry2rQM`
#!!Ea'3Iq
7UM!<@9\
return nFileLength; WtlPgT;wE
} 9,g &EnvG
I[E/)R{\
f7NK0kuA
//保存下载信息（文件指针位置） =23JE'^=
private void write_nPos() unn2MP'
{ \@6PA
try{ s2s}5b3
output = new DataOutputStream(new FileOutputStream(tmpFile)); j<[+vrj
output.writeInt(nStartPos.length); 94Wf ]
for(int i=0;i<nStartPos.length;i++) rN* ,U\q
{ H=Sy.
// output.writeLong(nPos); yv2BbrYyy
output.writeLong(fileSplitterFetch.nStartPos); <7Igd6u
output.writeLong(fileSplitterFetch.nEndPos); agdiJ-lyQ
} kH$)0nK
output.close(); N]qX^RSb
} $42%H#
catch(IOException e){e.printStackTrace ();} &aD]_+b
catch(Exception e){e.printStackTrace ();} svki=GD_(.
} 9nIBs{`/Ac
lB_&Lq8G
l'h[wwEXm{
//读取保存的下载信息（文件指针位置） NgH"jg-
private void read_nPos() *p)1c_
{ K& / rzs-
try{ U)mg]o-VE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <tp\+v!u
int nCount = input.readInt(); =fy~-FN_
nStartPos = new long[nCount]; ,#;%ILF4%
nEndPos = new long[nCount]; _c|aRRW
for(int i=0;i<nStartPos.length;i++) "7Qc:<ww
{ O{WJi;l
nStartPos = input.readLong(); tu(k"'aJ
nEndPos = input.readLong(); haj\Dm
} G+Vlaa/7
input.close(); >(>Fx\z}
} 1%W|>M`
catch(IOException e){e.printStackTrace ();} j(JUOief
catch(Exception e){e.printStackTrace ();} D4jf%7X!Lu
} PP{2{
~xz3- a/
7kbeAJ+{
private void processErrorCode(int nErrorCode) ZLK@x.=
{ )'\pa2
System.err.println("Error Code : " + nErrorCode); @H'pvFLK?
} pMJK?- )
OG}auM4
'&_<!Nv3
//停止文件下载 '&~A
public void siteStop() sR%,l
{ Nc4e,>$]&
bStop = true; jTjGbC]X
for(int i=0;i<nStartPos.length;i++) TM_ MJp
fileSplitterFetch.splitterStop(); -.#He
("HT0&#a
9H~{2Un
} I^'U_"vB
} N[G<&f9
//负责部分文件的抓取 8p3pw=p
**FileSplitterFetch.java cZnB 2T?
*/ @r.u8e)l
package NetFox; ?R2`RvQ
gm;6v30e
'k2Z$+
import java.io.*; Iz;hje4JL
import java.net.*; P<@Yux#
WgBV,{C
mRIW9V
public class FileSplitterFetch extends Thread { >{_`J
adEcIvN$
0Me*X
String sURL; //File URL 9p,<<5{
long nStartPos; //File Snippet Start Position v&CKtk!3{
long nEndPos; //File Snippet End Position T?=[6
int nThreadID; //Thread's ID F[ca4_lK
boolean bDownOver = false; //Downing is over cB5|%@$I
boolean bStop = false; //Stop identical iRwqt-WZ
FileAccessI fileAccessI = null; //File Access interface u#tLY/KA
-#XNZy!//
imE5$;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XO |U4#ya
{ r{~K8!=oU]
this.sURL = sURL; GdN'G
this.nStartPos = nStart; ^s'ozCk 0
this.nEndPos = nEnd; 2+G_Y>
nThreadID = id; XWo=?(iA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <fY<.X
} %dXfC!
~O{sOl _<4
L|DSEth
public void run() WFBg3#p
{ eZ~^Z8F[6
while(nStartPos < nEndPos && !bStop) x)@G+I\u
{ @21G[!%J
sePOW#|
9gMNS6D'b
try{ m .2)P~a
URL url = new URL(sURL); G:qkk(6_#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !/0XoIf"
httpConnection.setRequestProperty("User-Agent","NetFox"); .^s%Nh2jM
String sProperty = "bytes="+nStartPos+"-"; yQQ[_1$pq
httpConnection.setRequestProperty("RANGE",sProperty); 5" U8|
Utility.log(sProperty); ^0t81,`
E.Hw|y0_(|
% ~%>3
InputStream input = httpConnection.getInputStream(); H9)$ #r6i
//logResponseHead(httpConnection); K%h83tm+
Q"]C"?
lyzMKla"
byte[] b = new byte[1024]; GiBq1U-Q
int nRead; )i; y4S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =dbLA ,z9
{ 9\W~5J<7
nStartPos += fileAccessI.write(b,0,nRead); rnxO2
//if(nThreadID == 1) 7`3he8@ze
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e=nExY
} X~RET[L2
tR#uDE\wR
i3k ',8
Utility.log("Thread " + nThreadID + " is over!"); k07JMS?
bDownOver = true; !F{5"$
//nPos = fileAccessI.write (b,0,nRead); * wN+Ak q
} 5Am*1S^
catch(Exception e){e.printStackTrace ();} $UlA_l29
} x@bZ((w
} RB'12^[
2S^xqvh
ZMJ\C|S:
//打印回应的头信息 1'EMYQ
public void logResponseHead(HttpURLConnection con) n?@o:c5,r
{ 1N<)lZl)
for(int i=1;;i++) ~AuvB4xe~
{ k}-%NkQ 9O
String header=con.getHeaderFieldKey(i); D@H'8C\
if(header!=null) Y=/3_[G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *>.~f<V
Utility.log(header+" : "+con.getHeaderField(header)); #m9V)1"wB
else Ki-CJy
break; z$p+l]
} =Feavyx
} nM8aC&Rd\
Zl"h-~31
z'r.LBnh
public void splitterStop() iXC/? EK4
{ U^ BB|
bStop = true; {Z;W|w1t
} \`x'r$CV
+7+ VbsFG
"/hs@4{u9
} dQA J`9B
t]FFGnBZ
+u_mT$|T
/* BU:s&+LYUv
**FileAccess.java 13A11XTp
*//文件访问(定位，写) 7w)#[^
package NetFox; h bj^!0m
import java.io.*; n*D)RiW
~C=`yj
W5:S+
public class FileAccessI implements Serializable{ &nPv%P,e
4$.UVW\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .(;k]UP
RandomAccessFile oSavedFile; {b/60xl?
long nPos; $if(`8
)'%L#
a|?CC/Ra
public FileAccessI() throws IOException *goi^Xp
{ I+O!<SB
this("",0); vWfC!k-)b
} WP^%[?S2
UDyvTfh1X
y9\s[}c_
public FileAccessI(String sName,long nPos) throws IOException _* 4 <
{ )#3,y6
oSavedFile = new RandomAccessFile(sName,"rw"); TdD-#|5
this.nPos = nPos; !0Xes0gK0
oSavedFile.seek(nPos); N!RyncJ
} wrsETB c
\"Sqr(~_
? dSrY
public synchronized int write(byte[] b,int nStart,int nLen) 2%vwC]A
{ @u6#Tvxy[
int n = -1; @uY%;%Pa8
try{ M~N'z/
oSavedFile.write(b,nStart,nLen); pS%,wjb&P
n = nLen; )Y?Hf2']
} Xg!Mc<wA[
catch(IOException e) >YoK?e6
{ ;5y4v
e.printStackTrace (); "cJ5Fd:*
} Vzbl*Zmx
@292;qi
Y/Y746I
return n; lt0(Kf g
} b'9G`Y s^
~,':PUkiV
%I Y-0\
} 8Qu].nKe
[+GQ3Z\
T_AZCl4d
/* FIU(2
**SiteInfoBean.java ci3{k"
*/ E?Q=#+}U
package NetFox; X[;4.imE
2b|vb}|t{
,b{G(sF
public class SiteInfoBean { -]'Sy$,A
Mm.!$uR
"{{xH*ij'
private String sSiteURL; //Site's URL e4CG=K3s
private String sFilePath; //Saved File's Path %_tL}m{?
private String sFileName; //Saved File's Name e1&c_"TOih
private int nSplitter; //Count of Splited Downloading File 5-u=ZB%p
?wwY8e?S
fXL>L
public SiteInfoBean() l@#X]3h!
{//nSplitter的缺省值为5 zO)9(%LS
//default value of nSplitter is 5 PVEEKKJP]J
this("","","",5); j1d#\
} } A#C
Vi#(x9.
~q|^z[7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v/yk T9@;
{ hDp'=}85@
sSiteURL= sURL; ;oR-\;]/.
sFilePath = sPath; 5&94VQ$d
sFileName = sName; yxA0#6so
this.nSplitter = nSpiltter; 5@ZD'
X#eVw|
Pi*,&D>{7
} b:%>TPT
/h2`?~k+
$/wr?
public String getSSiteURL() `hH1rw@7<
{ =}c~BHT
return sSiteURL; )XO2DY1/&
} P$4?-AZ
9@vY(k k
|y'q`cY
public void setSSiteURL(String value) 'w9tZO\2
{ ',1rW
sSiteURL = value; xOu cZ+
} 89 (k<m
5gJQr%pS
SH}O?d\Q:
public String getSFilePath() b$gDFNa
{ S%%>&^5
return sFilePath; CB|z{(&N
} j@9nX4Z
l_f"}l
H uE*jQ
public void setSFilePath(String value) >/'WU79TYE
{ \*_a#4a
sFilePath = value; t5e(9Yhj
} ! B)Em
C8G['aQ
8@$QN4^u^
public String getSFileName() $rjv4e}7
{ cIgFSwQ4
return sFileName; jJ?3z,h
} J-,T^Wv
bq ~'jg^#
45-pJf8F
public void setSFileName(String value) mfx'Yw*{
{ O>k.sO <
sFileName = value; C2`END;
} eN jC.w9
,g\.C+.S
,%ajIs"Gi
public int getNSplitter() l{y~N
{ %|,j'V$
return nSplitter; ~sA}.7
} V25u'.'v
7z+NR&'M$
X$st{@}ZB
public void setNSplitter(int nCount) a>Q7Qn
{ x3M`l|
nSplitter = nCount; .+M4Pi
} ^rxXAc[
} LL,~&5{
v=X\@27= ?
da2BQ;
/* !A<?nz Uv
**Utility.java g\jdR_/
*/ !J6k\$r
package NetFox; "+HZ~:~f
4z$eT
7tt&/k?Q
public class Utility { #D}NT*w/
rP>5OLP
E&"bgwav{(
public Utility() xwz2N5
{ "dkvk7zCP
_ :][{W#
(sPZ1Fr\o
} U1&m-K
AalyEn&>
//线程睡眠 f:BW{Cij;y
public static void sleep(int nSecond) WS,p}:yPZG
{ vwT?Bp
try{ 2=U4'C4#
Thread.sleep(nSecond); CP={|]>+S
} A>'o5+
catch(Exception e) \s)j0F)
{ {cG&l:-r
e.printStackTrace (); 5qFqH
} ]p$fEW g
} _/PjeEm $p
`|]juc
//日志 M\T6cN@m
public static void log(String sMsg) 1g|H8CA
{ KWd]?e)
System.err.println(sMsg); fHe3 :a5+W
} 7ZJYT#>b
[zY9"B<3
(s\Nm_j
public static void log(int sMsg) 58=fT1 B
{ b ~F85U2
System.err.println(sMsg); DuCq16'0T
} s3t{freM
} )FgcNB1|7
T@f$w/15
RJSNniYr7
/* /dtFB5Z"w
**TestMethod.java a}=)b#T`
*/ %40|7O
package NetFox; `XI1,&Wp7
0]5QX/I
1tfm\/V}ho
public class TestMethod { 5)mn
5 kQC
sx|=*j,_
public TestMethod() ?_ p3^kl
{ ///xx/weblogic60b2_win.exe g9 g &]
try{ j1>1vD-`T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T}U`?s`)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zi<C5E`
SiteFileFetch fileFetch = new SiteFileFetch(bean); XFH7jHnL+U
fileFetch.start(); ,Y}HP3
} .,feRK>3
catch(Exception e){e.printStackTrace ();} Vbz$dpT
z+Y0Zh";/#
+AXui|mn
} ]BX|G`CCc
I)n%aTfo8
!WAbO(l
public static void main(String[] args) lKwIlp
{ OBu$T&
new TestMethod(); ,@(lYeD"
} (AV j_Cw
} rfoLg
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