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)); ,@jRe&6
} KlGPuGL
for(int i=0;i<nEndPos.length-1;i++) j9u/R01d
{ rlk0t159
nEndPos = nStartPos[i+1]; no`c[XY
} ty[bIaQi
nEndPos[nEndPos.length-1] = nFileLength; ?r0#{x~
} -;&aU;k
} $D +6=m[
34k<7X`I
8M*[RlUJB
//启动子线程 ]+;1)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0ohpJh61Q
for(int i=0;i<nStartPos.length;i++) )$Xd#bzD|
{ A9\m.3jo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0{#,'sc;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MKLntX
nStartPos,nEndPos,i); 5n! V^ !
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }NW^?37
fileSplitterFetch.start(); e}yoy+9
} r,X5@/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z=:<]j#=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -jnx0{/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |ybW
nEndPos = " + nFileLength); n#t{3qzpD
// fileSplitterFetch[nPos.length-1].start(); .ii9-+_
l_GvdD
dOh'9kk3
//等待子线程结束 8rwkux >
//int count = 0; =G3O7\KmH
//是否结束while循环 S453oG"
boolean breakWhile = false; l?v`kAMR
&cztUM(
,}2yxo;i
while(!bStop) H$TYp
{ 0KO_bF#EB=
write_nPos(); *c4uCI:0t
Utility.sleep(500); gQ4Q h;
breakWhile = true; HMGby2^+
;SoKX?up5
}VxbO8\b(
for(int i=0;i<nStartPos.length;i++) |@?B%sY
{ a3e<<<Z>R
if(!fileSplitterFetch.bDownOver) Cv862kP
{ FVM:%S JjT
breakWhile = false; M-1 VB5
break; zM{'GB+en
} .}>d[},F
} uH[d%y/
if(breakWhile) +6t<FH
break; 2:'C|
//cj$}Rn!
HKr")K%
//count++; im{'PgiR
//if(count>4) ON#\W>MK?
// siteStop(); z1[2.&9D-
} zJJ KLr;
P5/K?I~/So
^(y=DJ7
System.err.println("文件下载结束！"); Dz/I"bZLC
} jV Yt=j*"V
catch(Exception e){e.printStackTrace ();} +^tq?PfE
} KD?~ hpg
`l,=iy$
6}^0/76^,
//获得文件长度 d2lOx|jt
public long getFileSize() 4<._)_m
{ b:3n)-V{u
int nFileLength = -1; {Ts@#V=:
try{ `3+yu' Q'
URL url = new URL(siteInfoBean.getSSiteURL()); sW!pMkd_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4q#6.E;yy
httpConnection.setRequestProperty("User-Agent","NetFox"); 6Ug(J$Ouh
s\QhCS
RK?b/9y
int responseCode=httpConnection.getResponseCode(); P\\4 w)C
if(responseCode>=400) 2`>/y
{ hNBv|&D#
processErrorCode(responseCode); <![tn#_
return -2; //-2 represent access is error 'U ',9
} U ^1Xc#Ff
~01 o
{N1Ss|6
String sHeader; wuE]ju<
fy04/_,q
,ButNBv
for(int i=1;;i++) `$oGgz6ZT
{ l'=H,8LfA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); , f9V`Pz)
//Utility.log(in.readLine()); wy6>^_z
sHeader=httpConnection.getHeaderFieldKey(i); 9,|{N(N<!
if(sHeader!=null) ?95^&4Oh0
{ kG_ K&,;@
if(sHeader.equals("Content-Length")) gX<"-,5jc
{ N:'v^0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W5,e;4/hL
break; T|^rFaA
} jqq96hP,
} 4zuM?Dp
else tiG=KHK%o
break; *A C){M
} dr0<K[S_
} kbzzage6L
catch(IOException e){e.printStackTrace ();} PD$XLZ
catch(Exception e){e.printStackTrace ();} "?EoYF_
v}p'vh^8B
h|OqM:J;
Utility.log(nFileLength); +c4]}9f!
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return nFileLength; q[p+OpA
} e! V`cg0
Yqz(@( %
{<0=y#@u
//保存下载信息（文件指针位置） i5wXT
private void write_nPos() X`bN/sI
{ t mAj
try{ =Q|_v}
output = new DataOutputStream(new FileOutputStream(tmpFile)); rFJ(t7\9h
output.writeInt(nStartPos.length); rT$J0"*=
for(int i=0;i<nStartPos.length;i++) l H:Y8j
{ gi!{y
// output.writeLong(nPos); 2mUq$kws
output.writeLong(fileSplitterFetch.nStartPos); SKf9 yS#
output.writeLong(fileSplitterFetch.nEndPos); ut z.
} =" Q5Z6W
output.close(); l>K z5re^
} fwaq
catch(IOException e){e.printStackTrace ();} !f5I.r~
catch(Exception e){e.printStackTrace ();} d`]|i:*q
} j3{8]D
cU <T;1VQ
0'u2xe
//读取保存的下载信息（文件指针位置） ?K,xxH
private void read_nPos() pvCn+y/U;
{ ! bbVa/
try{ xo{3r\u?}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); USF&;M3
int nCount = input.readInt(); 2{^k*Cfd
nStartPos = new long[nCount]; d]Y-^&]{]
nEndPos = new long[nCount]; 5bU[uT,`6
for(int i=0;i<nStartPos.length;i++) *L_+rJj,
{ Pd-0u>k
nStartPos = input.readLong(); W,&z:z>
nEndPos = input.readLong(); P.^%8L
} UHr0J jQK
input.close(); H]e%8w))0
} sevaNs
catch(IOException e){e.printStackTrace ();} p)l>bC?3
catch(Exception e){e.printStackTrace ();} zK.%tx}+=k
} R T/T+Q!
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private void processErrorCode(int nErrorCode) iW.4'9
{ On%21L;JG
System.err.println("Error Code : " + nErrorCode); Hc.r/
} (p4|,\+
9_yO6)`
pw;
//停止文件下载 "fWAp*nI3t
public void siteStop() `I*W}5
{ /)I:Cz/f
bStop = true; S[!sJ-rG
for(int i=0;i<nStartPos.length;i++) &h)G>Sqc
fileSplitterFetch.splitterStop(); /H 3u^
|eS5~0<`
p H&Tb4
} &t.9^;(
} AIZs^ `_
//负责部分文件的抓取 Q}ebw
**FileSplitterFetch.java ul0]\(sS:
*/ ",wv*z)_>
package NetFox; . ] =$((
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]|NwC<
import java.io.*; E/x2LYH
import java.net.*; (`S32,=TS
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public class FileSplitterFetch extends Thread { +#qW 0g
8@`"ZzM
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String sURL; //File URL H/!_D f
long nStartPos; //File Snippet Start Position $`7cs}#
long nEndPos; //File Snippet End Position N}`.N
int nThreadID; //Thread's ID jys1Ki
boolean bDownOver = false; //Downing is over s$g"6;_\
boolean bStop = false; //Stop identical h<KE)^).
FileAccessI fileAccessI = null; //File Access interface U)IW6)q
9+'QH
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L,!3
{ :e9}k5kdk
this.sURL = sURL; cYBv}ylw}R
this.nStartPos = nStart; SQ*dC
this.nEndPos = nEnd; AhjK*nJF
nThreadID = id; 7.hgne'<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /?<tjK' "H
} *#ccz
=HJ)!(
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public void run() V&7jd7 2{
{ Wi a%rm
while(nStartPos < nEndPos && !bStop) tI651Wm9
{ 5sbMp;ZM
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try{ pqaQ%|<
URL url = new URL(sURL); 63hOK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z#qlu=
httpConnection.setRequestProperty("User-Agent","NetFox"); \i Ylh HD
String sProperty = "bytes="+nStartPos+"-"; M%dJqwH5{
httpConnection.setRequestProperty("RANGE",sProperty); s>}ScJZK
Utility.log(sProperty); oU }eAZj{
#qL?;Zh0S
H|a9};pO\
InputStream input = httpConnection.getInputStream(); 5|l&` fv`
//logResponseHead(httpConnection); g\sW2qXEw
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byte[] b = new byte[1024]; Az+}[t
int nRead; INca
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *5( h,s3&
{ =-#>NlB$w
nStartPos += fileAccessI.write(b,0,nRead); b"U{@
//if(nThreadID == 1) weMC9T)B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); unE h
} i:ar{ q
:W'Yt9v)
J23Tst#s
Utility.log("Thread " + nThreadID + " is over!"); >;@ _TAF
bDownOver = true; bn`1JI@S4
//nPos = fileAccessI.write (b,0,nRead); D&5>Op4U
} 1mT3$Z
catch(Exception e){e.printStackTrace ();} ?L=@Zs
} bLMN9wGOgK
} Rv9oK-S
/P<K)a4GM
0fgt2gA33
//打印回应的头信息 [%U(l<
public void logResponseHead(HttpURLConnection con) $[zy|Y(
{ bzFwQi}>
for(int i=1;;i++) O*MC"%T
{ }UwDHq=
String header=con.getHeaderFieldKey(i); @4h{#
if(header!=null) _M n7zt1^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -phwzR\(t
Utility.log(header+" : "+con.getHeaderField(header)); J!?hajw7N
else x1['+!01
break; HX1RA5O
} sQt]Y&_/@
} b&k !DeE
&A=>x
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public void splitterStop() 6FMW}*6<
{ x!CCSM;q
bStop = true; ?yKW^,q+
} _yje"
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NABwtx>.
} YJZViic
IY$H M3t7
]IQTf5n
/* B%HG7
**FileAccess.java 8BnI0l=\
*//文件访问(定位，写) Fl,(KSTz
package NetFox; c}9.Or`?
import java.io.*; YGVj$\
NP%Y\%;l6
r|rOIAo
public class FileAccessI implements Serializable{ 02Z>#AE
2/.Euf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n6T@A;_g
RandomAccessFile oSavedFile; iU^KmM I
long nPos; UR')) 1n
S]^`Qy)
H f}->
public FileAccessI() throws IOException (8C ,"Dc[0
{ #biI=S
this("",0); 2CX'J8Sy
} (ly4[G1y
#T0uPK ;
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public FileAccessI(String sName,long nPos) throws IOException 9pN},F91n:
{ `]L&2RS
oSavedFile = new RandomAccessFile(sName,"rw"); 69)- )en
this.nPos = nPos; aiP.\`>}
oSavedFile.seek(nPos); 5c?1JH62o8
} O)g\/uRy
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5[Sa7Mk
public synchronized int write(byte[] b,int nStart,int nLen) }?zy*yL
{ 0Da9,&D
int n = -1; }^).Y7{g[
try{ -LAYj:4
oSavedFile.write(b,nStart,nLen); ?[#nh@mI
n = nLen; X-$~j+YC
} {j%'EJ5
catch(IOException e) Dh=?Hzw
{ m44Ab6gpsb
e.printStackTrace (); =b{wzx}e
} P@Oq'y[
i v7^!
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return n; 0fhz7\a^_<
} E<u6 js,
I^h^QeBis
nCF1i2*6|"
} LadE4:oy
df}DJB
9VyY[&
/* L;d(|7BVv
**SiteInfoBean.java 5;{Q >n
*/ p^u;]~JO
package NetFox; &rY73qfP'
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CAX)AN
public class SiteInfoBean { 6CoDn(+z
$n |)M+d
K0hmRR=
private String sSiteURL; //Site's URL WP/?(%#Y
private String sFilePath; //Saved File's Path 8KH|:>s=
private String sFileName; //Saved File's Name V/C":!;
private int nSplitter; //Count of Splited Downloading File 5U[m]W=B
xY]Y
J&mZsa)4
public SiteInfoBean() [ +w=
{//nSplitter的缺省值为5 u>R2:i
//default value of nSplitter is 5 I_|@Fn[>
this("","","",5); #~(J J
} X?PcEAi;w
+6dq+8msF
y8jwfO3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >K<n~;ON|
{ luNEgCq
sSiteURL= sURL; kzq3-NTV
sFilePath = sPath; mUFg(;ya
sFileName = sName; J9+<9g4-t
this.nSplitter = nSpiltter; :m~R<BQ"
[wHGt?R
-\ {.]KL
} s];jroW@u
Tf[o'=2
#^|"dIZ_M
public String getSSiteURL() vumA W*
{ NGsG4y^g?z
return sSiteURL; ;Mzy>*#$Q
} tGq0f"}'J
W!@*3U]2R
3zdm-5R.b
public void setSSiteURL(String value) g<ZB9;FX %
{ 5,H,OZ}
sSiteURL = value; HB+{vuN*L
} 0O,Q]P 82f
Yz6+ x]
*qM)[XO
public String getSFilePath() m-%.LDqM
{ IrIF 853g
return sFilePath; "n,?)
} y2nwDw(xF
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>M~wFs$~
public void setSFilePath(String value) :=CRsQAn
{ J.%%]-f=&
sFilePath = value; )SJ18 no|l
} d~ m,hCTe
(c^ZFh2]
NT3Ti ?J,
public String getSFileName() tv,Z>&OM
{ ZT;8Wvo
return sFileName; 6S`J7[
} ~hx__^]d
mpcO-%a
6 07"Z\
public void setSFileName(String value) Ze?(N~
{ D\"F?>
sFileName = value; &\w:jI44Bs
} Pl2ZA)[g
$G $147z
%yr(i 6L
public int getNSplitter() 3b9SyU2
{ k;)t}7(
return nSplitter; PG@Uygahu
} \xtY\q,[
;ty08D/
NG)Xk[q4
public void setNSplitter(int nCount) y9/x:n&]
{ 9hbn<Y
nSplitter = nCount; a,>`ab%>
} -Y?C1DbKz
} -chk\75
m+3U[KKvG
zQPQP`
/* oM<Y o%n
**Utility.java )p?p39>h
*/ &_1Ivaen6
package NetFox; e#R'_}\yj
]ULE>a
PPj_NV
public class Utility { 295U<
u)NmjW
:h(r2?=7
public Utility() pb`!_GmB
{ mrc% 6Ri
cq?&edjP
p K=
} zJxO\
&@&0n)VTd
//线程睡眠 T^b62j'b5_
public static void sleep(int nSecond) PF6w'T 5
{ 7BNu.5*y
try{ MPS{MGVjbJ
Thread.sleep(nSecond); ?H30
} 0q4E^}iR
catch(Exception e) n91@{U)QJ3
{ = nIl$9
e.printStackTrace (); rhr(uCp/
} v \xuq`
} x!@3.$
B#Q=Fo 6
//日志 Lt<KRs
public static void log(String sMsg) XFS"~{
{ <E&[sQ|3
System.err.println(sMsg); c;M&;'#x
} Pl9Ky(Q`V
"3\C;B6I
$VgazUH% =
public static void log(int sMsg) 4Iq-4IG(
{ BS(XEmJn&j
System.err.println(sMsg); @xBw'
} M~o\K'
} 'K8emt$d+
C{5^UCJkg
|1rKGDc
/* zA<Hj;9SM
**TestMethod.java <D1>;C
*/ Q+r8qnL'
package NetFox; jf|5}5kSlf
r/G6O
qRX:eo
public class TestMethod { GELxS!
<*4'H
|cBeyqr
public TestMethod() E\GD hfTQ
{ ///xx/weblogic60b2_win.exe 9^AfT>b~f
try{ eHt |O~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i^O(JC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gl@-RLo
SiteFileFetch fileFetch = new SiteFileFetch(bean); aYC[15?'
fileFetch.start(); wv6rjg:7
} pT=YV k
catch(Exception e){e.printStackTrace ();} ~"t33U6
'TdO6-X
k`u:Cz#aB
} @71n{9
uy t'
/1!Wet}f
public static void main(String[] args) d9E'4Zm
{ en1NFP
new TestMethod(); Kx@Papn|6
} w4"4(SR.
} /HiRbwQK#
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