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)); Xf0pQ]8\
} 4&\m!s
for(int i=0;i<nEndPos.length-1;i++) @*oi1_q
{ TzOf&cs/r
nEndPos = nStartPos[i+1]; l$FHL2?Cp
} it.l;L_nW
nEndPos[nEndPos.length-1] = nFileLength; `27? f$,
} Kl*##qw!
} 9u9#&xx
"x{S3v4Rb5
GXAcyOV
//启动子线程 Uz0mSfBp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G -;Yua2\
for(int i=0;i<nStartPos.length;i++) ]?kf;A@
{ ':Te#S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cc^t&Eg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g$<@!
nStartPos,nEndPos,i); R}0cO^V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S^_na]M"4
fileSplitterFetch.start(); ?0.+DB $
} th]9@7UE,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xkX, l{6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); htjJ0>&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (]ORB0kl
nEndPos = " + nFileLength); znM"P|A
// fileSplitterFetch[nPos.length-1].start(); S\C
wtY#8'^$&
lU@ni(69d
//等待子线程结束 d.{RZq2cp
//int count = 0; 1:,aFp>qr
//是否结束while循环 wj/r)rv E
boolean breakWhile = false; ua0k)4|
Sh"} c2
M?_VYK
while(!bStop) NE(6`Wq`
{ 4'{j'kuv
write_nPos(); 9 Hm!B )Y
Utility.sleep(500); bC&_OU:
breakWhile = true; U $+rlw}
l_8t[
s?=J#WV1y
for(int i=0;i<nStartPos.length;i++) _h5@3>b3r
{ H}:apRb
if(!fileSplitterFetch.bDownOver) 3&}wfK]X
{ /_LUys/0
breakWhile = false; 7c+u+Yet
break; %3q@\:s
} 5SDHZ?h
} j"c"sF\q
if(breakWhile) 2qN6{+]
break; U'@_fg
nGRF<2!
7OT}V}iP
//count++; d/;oNC+
//if(count>4) }ulFW]A^7
// siteStop(); 39u!j|VH
} utQ_!3u
gP<l
t.]oLG22r
System.err.println("文件下载结束！"); ?bbguwo~F
} u%&zY97/
catch(Exception e){e.printStackTrace ();} JeiW z1t
} 6N]v9uXZ
^oA^z1>3
pO"V9[p]
//获得文件长度 wKwireOs
public long getFileSize() |,qz7dpe
{ C7PHZ`<
int nFileLength = -1; 1(C%/g#"
try{ 8TuOf(qE
URL url = new URL(siteInfoBean.getSSiteURL()); Z,ag5 w`]L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Lx2.E1?@
httpConnection.setRequestProperty("User-Agent","NetFox"); Y(<>[8S m
u+S*D\p<`
a?@j`@]ZR~
int responseCode=httpConnection.getResponseCode(); kRG-~'f%`
if(responseCode>=400) iX~V(~v
{ YT#"HYO
processErrorCode(responseCode); [_${N,1
return -2; //-2 represent access is error #SQFI;zj
} T#T!a0
w(s"r p}
eRD s?n3F
String sHeader; mw.9cDf
JgEpqA12
aWW|.#L
for(int i=1;;i++) rlW
{ 1J^{h5?lU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -p9|l%W
//Utility.log(in.readLine()); RzNv|
sHeader=httpConnection.getHeaderFieldKey(i); {V8v
if(sHeader!=null) AOeptv^k3}
{ 9QZ;F4 r
if(sHeader.equals("Content-Length")) Xa+ u>1"2"
{ Ao 1*a%-.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O7:JG[tR*
break; i9W@$I,f
} a&|aK+^8;
} entO"~*EX
else C2FewsRz
break; s4t>/.;x
} :rwF5
} "5]GEzM3O
catch(IOException e){e.printStackTrace ();} ^O4.$4t|
catch(Exception e){e.printStackTrace ();} WM:we*k8h
r=<,`_@Y
7+=fD|Cl
Utility.log(nFileLength); ]0g<][m
lY0^Z
&R>x;&Gj
return nFileLength; T[L
} HBeOK
9aYCU/3
,M5J~Ga
//保存下载信息（文件指针位置） T+RfMEdr
private void write_nPos() KZJ;O7'`
{ Kp8!^os
try{ W|; .G9
output = new DataOutputStream(new FileOutputStream(tmpFile)); vY:A7yGW
output.writeInt(nStartPos.length); !3}vl Y1
for(int i=0;i<nStartPos.length;i++) O0c#-K.f
{ 3\G&fb|?}R
// output.writeLong(nPos); V#=o<
output.writeLong(fileSplitterFetch.nStartPos); &.;tdT7
output.writeLong(fileSplitterFetch.nEndPos); A)&OR]0[
} 5q}680s9+
output.close(); g&#.zJ[-
} I[G<aI!
catch(IOException e){e.printStackTrace ();} QVm3(;&'
catch(Exception e){e.printStackTrace ();} {088j?[hzk
} vEOoG>'Zq
0k0y'1SL
D?;$:D"
//读取保存的下载信息（文件指针位置） Jah~h44&
private void read_nPos() +hqsIx
{ -BgzAxa
try{ RL SP?o2J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +m]$P,yMt
int nCount = input.readInt(); bncIxxe
nStartPos = new long[nCount]; .{*V^[.
nEndPos = new long[nCount]; ;}ileLTl
for(int i=0;i<nStartPos.length;i++) mn)kd
{ &U*=D8!0
nStartPos = input.readLong(); SZea[~&
nEndPos = input.readLong(); 1|Us"GQ(n
} ZV$qv=X
input.close(); Z>{3t/`
} nPD5/xW
catch(IOException e){e.printStackTrace ();} -tlRe12
catch(Exception e){e.printStackTrace ();} oyiEOC
} ng;,;o.
%c*azo.
Wf +j/RxTi
private void processErrorCode(int nErrorCode) mvyqCOp0
{ )#N)w5DU
System.err.println("Error Code : " + nErrorCode); CfNHv-jDL
} KW]/u
a=+qR:wT
!U/iY%NE
//停止文件下载 7loIX Qw
public void siteStop() qCi6kEr
{ 3.Oc8(N^}
bStop = true; lED-Jo2
for(int i=0;i<nStartPos.length;i++) `BG{\3>
fileSplitterFetch.splitterStop(); zB kS1qMn
Po#;SG#Ee
: " 9F.U
} I9-vV>:z
} Y9F!HM-`
//负责部分文件的抓取 |W];8
**FileSplitterFetch.java n[H3b}
*/ :UGc6
package NetFox; . T6fPEb
Pwn"!pk
5*l~7R
import java.io.*; 0'{0kE[wn
import java.net.*; /f@VRME
wws)**]J8
l*T>9yC
public class FileSplitterFetch extends Thread { </3Shq
BFmd`#{l
?>SC:{(
String sURL; //File URL &=oW=g2
long nStartPos; //File Snippet Start Position D<B/oSy
long nEndPos; //File Snippet End Position /B73|KB+
int nThreadID; //Thread's ID 03Pa; n
boolean bDownOver = false; //Downing is over g} 7FR({b
boolean bStop = false; //Stop identical sDL@e33Yb
FileAccessI fileAccessI = null; //File Access interface RsIR}.*
B#9rqC
Z[[ou?c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -]\cUQ0
{ (\}>+qS[
this.sURL = sURL; x2(!r3a
this.nStartPos = nStart; .>NhC"
this.nEndPos = nEnd; >DeG//rv
nThreadID = id; P$?3\`U;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @AYO )Y8
} ?&W1lYY
FTZ][
fmC)]O%q
public void run() }YH@T]O}
{ !$P+hX`
while(nStartPos < nEndPos && !bStop) P#H|at
{ Nn5z
q] eSDRW
/R7qR#
try{ GP6-5Y"8
URL url = new URL(sURL); }JyWy_Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m&(yx|a4+
httpConnection.setRequestProperty("User-Agent","NetFox"); |d\rCq >
String sProperty = "bytes="+nStartPos+"-"; l ps 6lnh
httpConnection.setRequestProperty("RANGE",sProperty); VDq4n;p1
Utility.log(sProperty); k$1ya7-@
d5mhk[p7\J
*F|j%]k~
InputStream input = httpConnection.getInputStream(); 3)ac
//logResponseHead(httpConnection); Z".mEF-b
*vqlY[2Ax
m2{3j[
byte[] b = new byte[1024]; ij&_>
int nRead; d:jD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yG -1g0
{ eq+t%
nStartPos += fileAccessI.write(b,0,nRead); 1~/?W^ir
//if(nThreadID == 1) vcTWe$;Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q y"VrR
} Sp8Xka~5*#
rV.04m,
iy_'D
Utility.log("Thread " + nThreadID + " is over!"); 0?59o!@h
bDownOver = true; A??(}F L
//nPos = fileAccessI.write (b,0,nRead); [!9dA.tF
} +NL^/y<;
catch(Exception e){e.printStackTrace ();} {Wp+Y9c[
} HPJ\]HV(
} )vVt{g
Ln/6]CMl
>Hb>wlYR
//打印回应的头信息 <8#Q5
public void logResponseHead(HttpURLConnection con) IH|PdVNtg
{ )QS4Z{)U
for(int i=1;;i++) rrBu6\D
{ 1d)wE4c=Z
String header=con.getHeaderFieldKey(i); wO:!B\e
if(header!=null) f@U\2r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5A(zQ'6
Utility.log(header+" : "+con.getHeaderField(header)); .XD7};g
else d3Dw[4
break; gx+bKGB`
} F)P"UQ!\
} _cra_(b
cm^:3(yYX
|^&n\vXv
public void splitterStop() QH%Zbt2qS
{ F&?55@b
bStop = true; {B^V_TX2
} u%n6!Zx
9+<%74|,
$B6CLWB
} @pq#?
*xm(K+j
*=UxX ]0y
/* Pp-\#WJ
**FileAccess.java ie4keVlXc
*//文件访问(定位，写) 9$[I~I#z
package NetFox; qFEGV+
import java.io.*; ~P&Brn"=Rs
.KiJq:$H
a#H2H`%
public class FileAccessI implements Serializable{ z"/Mva3|
4u}"ng
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |GPR3%9
RandomAccessFile oSavedFile; 27mGX\T
long nPos; !O=?n<Ex"
=@%;6`AVcp
B&^WRM;7t
public FileAccessI() throws IOException ke.{wh\0
{ VrL==aTYXs
this("",0); .XPcH(q
} jwsl"zL
w`Q"mx*
0Y rdu,c
public FileAccessI(String sName,long nPos) throws IOException RiHOX&-7
{ Wn;B~
oSavedFile = new RandomAccessFile(sName,"rw"); q-c9YOz_
this.nPos = nPos; Z9cg,#(D
oSavedFile.seek(nPos); [e1kfw
} Hg)5c!F7
l#7].-/
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public synchronized int write(byte[] b,int nStart,int nLen) z{h#l!Edh
{ QmQsNcF~z
int n = -1; Q`$Q(/
try{ gucd]VH
oSavedFile.write(b,nStart,nLen); 9o-fI@9
n = nLen; G9?6qb:
} en\shc{R]`
catch(IOException e) Fv!zS.)`
{ rBBA`Ut@F
e.printStackTrace (); y!6+jrI
} mHTZ:84
4%l @
emZ^d/A
return n; uP,{yna(
} s|3@\9\
]8,:E ]`O
B35zmFX|}N
} 9G8n'jWyY
cY/!z
jO'+r'2B9
/* 3/sKRU
**SiteInfoBean.java )h(Dt(2Wm
*/ &cj/8A5-
package NetFox; _n9+(X3
$`q8-+{
\Y'#}J"dh
public class SiteInfoBean { KM$5ZbCF:
z-(#Mlq:!
.H1kl)~V
private String sSiteURL; //Site's URL nnBgTtsC]
private String sFilePath; //Saved File's Path V\axOz!
private String sFileName; //Saved File's Name .E!p
private int nSplitter; //Count of Splited Downloading File }5n((7@X
r,p6J7/lfS
nquKeH
public SiteInfoBean() *SkUkqP9z
{//nSplitter的缺省值为5 )tQG5.to
//default value of nSplitter is 5 e'<pw^I\
this("","","",5); 6T%5vg_};'
} Y.$InQ gL
J"w!Q\_
]h (TZu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u7|{~D&f
{ e2#"o{+@
sSiteURL= sURL; wv,,#P
sFilePath = sPath; (]'Q!MjGa
sFileName = sName; ]+\@_1<ZI
this.nSplitter = nSpiltter; />fP )56*
'BT}'qN
T-7'#uB.m
} 3Rid1;L0U
OHnHSb'?\
$cO"1mu
public String getSSiteURL() aubmA0w
{ <}pwFl8C)
return sSiteURL; % '>S9Ja3
} !O$*/7
yjvH)t/!.
Hfer\+RX
public void setSSiteURL(String value) ^G63GYh]y
{ .%+`e
sSiteURL = value; xG<H${ k;
} :"ZH
u>;#.N/
S=O/W(ZB
public String getSFilePath() -&Fxg>FrYb
{ %UJ!(_
return sFilePath; m{={a5GD
} ^RkHdA
1E Lzzn
RMB?H)p+
public void setSFilePath(String value) bwM>#@H
{ HtOo*\Ne
sFilePath = value; jY-i`rJN
} %8H*}@n
w<_.T#
fys@%PZq
public String getSFileName() qs6yEuh#
{ k/nOz*
return sFileName; {! RW*B
} s-r$%9o5
Ah)OyO6
ssW+'GD
public void setSFileName(String value) 6w K=
{ -tT{h4
sFileName = value; ,=lMtW
} ^DHFP-G?e
L>{E8qv>w
p}.P^`~j
public int getNSplitter() IS7g{:}=p
{ DLE|ctzj[7
return nSplitter; )rD] y2^<
} !@-j!Ub
oaI7j=Gp
7\^b+*
public void setNSplitter(int nCount) Ns9cx
{ !U#kUj:4I
nSplitter = nCount; `"[VkQFB/
} } oJ+2OepN
} wP1dPl_j:0
~fsAPIQ
0TSj]{[
/* r&"}zyL
**Utility.java .hgc1
*/ v%> ?~`Y
package NetFox; ?[Q;275
EF0{o_
n6WSTh
public class Utility { g'Ft5fQ"o/
%Zx/XMs}e
IDzP<u8v
public Utility() O:q}<ljp
{ GZQ)TzR
J),7ukLu^
c[<lr
} [w~teX0!
N;D(_:^
//线程睡眠 OM]p"Jd
public static void sleep(int nSecond) {AIP\
{ RrLQM!~
try{ 5<4njo?k
Thread.sleep(nSecond); {#q<0l
} `a:@[0r0U
catch(Exception e) 2U>1-p&dn
{ iUA2/ A
e.printStackTrace (); 5gI@~h S
} xpFu$2T6P.
} e}/c`7M
UuT>qWxQ8
//日志 .EH^1.|v
public static void log(String sMsg) {^9,Dy_D
{ PK3)M'[
System.err.println(sMsg); ci5ERv`
} 2DTH|Yv
yt C{,g>
\ ;Hj,z\
public static void log(int sMsg) /j -LW1:N
{ i1vBg}WHN
System.err.println(sMsg); n5UcivyX
} (W3R3>;
} abD55YJY
;eG%#=>
bm%2K@ /U
/* 8[f]9P/i
**TestMethod.java xQ1&j,R]
*/ ;^}cZ
package NetFox; lZ^XZjwoM
2K, 1wqf'
[$.oyjd
public class TestMethod { H|F>BjXn5
\R&`bAdk
K]@6&H-b|
public TestMethod() 2|EHNy!
{ ///xx/weblogic60b2_win.exe BAmH2"
try{ 6$SsdT|8B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '4HwS$mW3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U@D=.6\B
SiteFileFetch fileFetch = new SiteFileFetch(bean); }'kk}2ej`
fileFetch.start(); ]|Vm!Q
} L4.yrA-]C%
catch(Exception e){e.printStackTrace ();} XFYCPET
:BMUc-[
wi*Ke2YKP
} t]eB3)FX
1ErH \!
bL *;N3#E
public static void main(String[] args) E'[pNU*"x-
{ X@x: F|/P
new TestMethod(); ^ 9;s nr
} "793R^Tz
} }}t"^ms
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