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)); X=~V6m
} b |7ja_
for(int i=0;i<nEndPos.length-1;i++) Y)b@0'
{ ZPO|<uR
nEndPos = nStartPos[i+1]; 7*s8ttX
} 8)xt(~qF
nEndPos[nEndPos.length-1] = nFileLength; ~rv})4h
} feEMg
} 0^~\COa
1S$h<RIPAc
8o-bd_
//启动子线程 Yck~xt&]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q\$6F)ha3
for(int i=0;i<nStartPos.length;i++) cxP6-tV%
{ K:5eek
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u&]vd /
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N[U9d}Zv
nStartPos,nEndPos,i); >dQK.CG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8#LJ*o
fileSplitterFetch.start(); SH8/0g?
} ^Jx$t/t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XnUO*v^]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $'"8QOnJ?k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~]uZy=P? 5
nEndPos = " + nFileLength); D>sYPrf
// fileSplitterFetch[nPos.length-1].start(); V"RpH,
vtxvS3
|L:Cn J
//等待子线程结束 zAScRg$:?
//int count = 0; oq;'eM1,.
//是否结束while循环 YaY8 `M{
boolean breakWhile = false; @Doyt{|T
.T.5TMiOSq
$.K?N@(W
while(!bStop) Cg!^S(U4
{ H:S,\D?%2x
write_nPos(); <@,$hso7:
Utility.sleep(500); HGDVOJq
breakWhile = true; P $>`
?tYpc_p#
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for(int i=0;i<nStartPos.length;i++) rwqv V^
{ Jb(Y,LO^
if(!fileSplitterFetch.bDownOver) sR_xe}-
{ {'bip`U.
breakWhile = false; ?Zcj}e.r
break; \pY^^ l*
} -50AX1h31:
} |3eGz%Sd
if(breakWhile) jO'|mGUM
break; ~OFvu}]
;")A{tX2
Y=B3q8l5
//count++; [}o~PN:sT(
//if(count>4) H[Weu
// siteStop(); g-)mav
} cT'w=
fCUT[d+H
Yx)o:#2
System.err.println("文件下载结束！"); I6w~H?ul@*
} B)=~8wsI:Z
catch(Exception e){e.printStackTrace ();} >Da~Q WW|
} M##';x0
e!x6bR9EZ
uJow7-FD
//获得文件长度 m],Ud\
public long getFileSize() \54}T4R
{ YD[H
int nFileLength = -1; pSAR/':eg
try{ xJ(:m<z
URL url = new URL(siteInfoBean.getSSiteURL()); aXR%;]<Dw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t[C1z
httpConnection.setRequestProperty("User-Agent","NetFox"); d'HOpJE
d53 L65[
4%ZM:/
int responseCode=httpConnection.getResponseCode(); y?z\L
if(responseCode>=400) \0*l,i1&
{ XGs^rIf
processErrorCode(responseCode); oXYMoi
return -2; //-2 represent access is error 6rDfQ`f\p
} 6Wf^0ok
t#b0H)
.p@N:)W6
String sHeader; <,8l *1C
:jem~6i
4A.Q21s
for(int i=1;;i++) (GU9p>2
{ lAASV{s{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %w"nDu2Gcv
//Utility.log(in.readLine()); )ly ^Ox
sHeader=httpConnection.getHeaderFieldKey(i); g`,AaWlF
if(sHeader!=null) ;Ss$2V'a
{ >1|g5
if(sHeader.equals("Content-Length")) -q>^ALf|@>
{ fEnQE EU~P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nkY@_N
break; !,&yyx.
} I4e+$bU3
} ^^?q$1k6r*
else l},NcPL`
break; vK$^y^
} ;5S}~+j
} (.X]F_*sc
catch(IOException e){e.printStackTrace ();} zICI_*~
catch(Exception e){e.printStackTrace ();} 8k!6b\Imz
*i%quMv
Jh@_9/?
Utility.log(nFileLength); tS?lB05TOR
5vOCCW
}STYG`
return nFileLength; ST',4Oph5
} $&{IKP)u
*y7 $xa4
Y94MI1O5$
//保存下载信息（文件指针位置） H%i>L?J2/
private void write_nPos() x0+glQrNN
{ LI W*4r!
try{ iS: #o>
output = new DataOutputStream(new FileOutputStream(tmpFile)); Faac]5u:*
output.writeInt(nStartPos.length); "QY1.:o<(
for(int i=0;i<nStartPos.length;i++) 9]yW_]P
{ [_!O<z_sB
// output.writeLong(nPos); E`D%PEps+
output.writeLong(fileSplitterFetch.nStartPos); b`~wGe
output.writeLong(fileSplitterFetch.nEndPos); u<Xog$esu
} H~fdbR
output.close(); FjKq%.=#
} (xT*LF+
catch(IOException e){e.printStackTrace ();} - r#K#v3
catch(Exception e){e.printStackTrace ();} :L$4*8@`+
} ujzW|HW^v
D3]BTkMMS;
HD-Erop
//读取保存的下载信息（文件指针位置） XD%wj
private void read_nPos() 46XN3r
{ Z85|I.mr
try{ La,QB3K/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <y=ovkM3
int nCount = input.readInt(); ?d-70pm
nStartPos = new long[nCount]; JLm @Ag
nEndPos = new long[nCount]; "4 k-dj
for(int i=0;i<nStartPos.length;i++) 0i@:KYP
{ ><Z'D
nStartPos = input.readLong(); %_f;G+fK\p
nEndPos = input.readLong(); .9M.|
} U[8{_h<#
input.close(); Ijo(^v@
} 5K.+CO<
catch(IOException e){e.printStackTrace ();} ;u!?QSvb
catch(Exception e){e.printStackTrace ();} )"u:ytK{
} V2 `> ]/|
n9oR)&:o
"JhimgwvY
private void processErrorCode(int nErrorCode) F!g;A"?V
{ dHII.=lT
System.err.println("Error Code : " + nErrorCode); ycpE=fso'
} l4T:d^Eb
Q,e*#oK3$
WZ~> BM
//停止文件下载 fI:H8
public void siteStop() b9("DZW;
{ Ps>&"k$T
bStop = true; kC$I2[t!
for(int i=0;i<nStartPos.length;i++) O|z%DkH[
fileSplitterFetch.splitterStop(); '}{?AUDx
km 5E)_]
u{C)qb5Pu
} ~@9zil41
} >FFVY{F
//负责部分文件的抓取 3H8Al
**FileSplitterFetch.java )%j"
*/ /lH'hcXcX
package NetFox; pj|X]4?wdI
;}4k{{K
d"&3Q_2CD
import java.io.*; uMiyq<
import java.net.*; A3yi?y{[*
X47!E |*
rc{o?U'^-
public class FileSplitterFetch extends Thread { !$>G#+y
8hB.fau
80&D""
String sURL; //File URL "$)yB
long nStartPos; //File Snippet Start Position !J^tg2M8:
long nEndPos; //File Snippet End Position *cNk>y
int nThreadID; //Thread's ID W"qL-KW
boolean bDownOver = false; //Downing is over O E|+R4M
boolean bStop = false; //Stop identical KH}t:m+h
FileAccessI fileAccessI = null; //File Access interface uPDaq ]A
VS`Z_Xn
UR:n5V4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ScJu_Af
{ [W(Y3yyY
this.sURL = sURL; fPz=KoN
this.nStartPos = nStart; `:5,e/5,
this.nEndPos = nEnd; Vy;_GfT$
nThreadID = id; 4#2 ,Y!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t9D S]Li
} C*pLq5s
SIv[9G6
<}2A=~ _
public void run() 5$^c@ 0
{ gb-tNhJa@b
while(nStartPos < nEndPos && !bStop) X;]3$\F
{ }td6fj_{
fsI`DjKi)
.@K#U52
try{ i./Y w
URL url = new URL(sURL); D_ ug-<QT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UK:M:9
httpConnection.setRequestProperty("User-Agent","NetFox"); 0w}{(P;
String sProperty = "bytes="+nStartPos+"-"; ]h8/M7k
httpConnection.setRequestProperty("RANGE",sProperty); l?/gWD^
Utility.log(sProperty); jt%WPkY:
"1%*'B^}bw
U_Y;fSl>
InputStream input = httpConnection.getInputStream(); n/-N;'2J
//logResponseHead(httpConnection); {6tx,;r(F
W-XN4:,qI
8A_TIyh?
byte[] b = new byte[1024]; llqDT-cp
int nRead; V"g~q?@F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R `Q?J[e
{ u'Pn(A@1R
nStartPos += fileAccessI.write(b,0,nRead); _z%\'(l+
//if(nThreadID == 1) )$F6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MM*-i=
} z1qUz7
05g?jV
my=~"bw4
Utility.log("Thread " + nThreadID + " is over!"); -faw:
bDownOver = true; ~ i'C/[P
//nPos = fileAccessI.write (b,0,nRead); .-%oDuB5zF
} ]>*I)H)
catch(Exception e){e.printStackTrace ();} d#Wn[h$"
} ;]u1~
} _<Vg[-:1
b)y<.pS\
{4)5]62>u
//打印回应的头信息 oHRbAE^
public void logResponseHead(HttpURLConnection con) qKx59
{ Oo$%Yh51~
for(int i=1;;i++) +}Auk|>Dc
{ bY&YSlO
String header=con.getHeaderFieldKey(i); 6(sfpK'
if(header!=null) ugRV5bUk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KZ @l/s
Utility.log(header+" : "+con.getHeaderField(header)); [$H( CH`
else M'vXyb%$1
break; LA>dkPB
} A1 b6Zt
} X)Ocn`|
~Gwas0eNa
rcW#6VZ=
public void splitterStop() .Btv}b
{ GdL4|xv
bStop = true; 3XBp6`
} GMt)}Hz
7TR'zW2W
ZS|Z98
} /$<JCNGv
+Hi{/{k0N
+*Q9.LjV
/* [)bz6\d[
**FileAccess.java oRV]p
*//文件访问(定位，写) ?n73J wH
package NetFox; a6OrE*x:D
import java.io.*; 7dsnv)(v
wsna5D6i
>DkN+S
public class FileAccessI implements Serializable{ |)*m[_1
YDdLDE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JO]`LF]
RandomAccessFile oSavedFile; :v''"+\
long nPos; )lE3GDAPgZ
j(UX 6lR
m|(I} |kT3
public FileAccessI() throws IOException vl>_e
{ |UABar b
this("",0); av7q>NEZ!1
} Vl&+/-V
he_HVRpB
d#RF0,Y9
public FileAccessI(String sName,long nPos) throws IOException 38OIFT
{ a [0N,t
oSavedFile = new RandomAccessFile(sName,"rw"); \>w@=bq26
this.nPos = nPos; EgkZ$ah
oSavedFile.seek(nPos); s}z(|IrH
} ;e`D#khB
#wq;^)>
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public synchronized int write(byte[] b,int nStart,int nLen) xuw//F
{ <x.]OZgO
int n = -1; EXv\FUzo
try{ _+0uju?o}
oSavedFile.write(b,nStart,nLen); eimA *0Cq
n = nLen; pqRO[XEp2
} v GulM<YY
catch(IOException e) VGkW3Nt0
{ Xd90n>4S
e.printStackTrace (); l;"ub^AH
} pIM*c6
uKaf{=*
7H/!rx
return n; rHA/
} v3iDh8.__
(UbR%A|v;
_.oRVYK/
} &h_d|8
9}? 5p]%
UEx(~>
/* \1eKY^)2
**SiteInfoBean.java L|dab{9
*/ WW,r9D:/
package NetFox; \" 5F;J
!nZI? z;
a3DoLq"/
public class SiteInfoBean { W]C_oh
LRfFn^FPM
/It.>1~2@
private String sSiteURL; //Site's URL N6-2*ES
private String sFilePath; //Saved File's Path Ae,2Xi
private String sFileName; //Saved File's Name ?];~N5<'
private int nSplitter; //Count of Splited Downloading File $j$\ccG
P:bVcta9g
o3(|FN
public SiteInfoBean() A3<P li
{//nSplitter的缺省值为5 n57c^/A*
//default value of nSplitter is 5 ^mQ;CMV
this("","","",5); 4#'^\5
} 6c;?`C
'T#<OR
A[wxa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) noB}p4
{ K!$\REs
sSiteURL= sURL; y.TdWnXx
sFilePath = sPath; 3P<Zzt%eT
sFileName = sName; ^*4(JR
this.nSplitter = nSpiltter; 7J)a"d^e
Nys'4kx7
&T|UAM.
} tCF0Ah
).O\O)K
0t/z"
public String getSSiteURL() H/ B^N,oi
{ CC]@`R5
return sSiteURL; Is#v6:#^
} U:T5o]P<
9\W5
&].1[&M]
public void setSSiteURL(String value) ]#WX|0''^
{ qjdahVY
sSiteURL = value; Yg:74; .
} }f0^9(
!:!@dC%8_
~O7cUsAi'
public String getSFilePath() da7x 1n$D
{ 6:7:NIl:
return sFilePath; h&^/, G
} )H=[NB6J8
'f$?/5@@
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public void setSFilePath(String value) h<z/LL8|
{ LTlC}3c28f
sFilePath = value; RQ$o'U9A
} -`ys pE0?
rym\5 `)
L_CEY
public String getSFileName() 3YZ3fhpw
{ /:c,v-
return sFileName; E6KBpQcd[
} MHzsxF|
D9pxe qf+=
DIcyXZH<
public void setSFileName(String value) *U[Q=w
{ p|O-I&Xd
sFileName = value; !h~#L"z
} VIlQzM;%^
2l}FgD
4s+J-l
public int getNSplitter() /hj9Q!
{ KE|u}M@v6
return nSplitter; Z+pvdu
} JKu6+V jO
9zGKQ|X)
myo~Qqt?
public void setNSplitter(int nCount) 4mg 7f^[+
{ 36Fa9P FCc
nSplitter = nCount; T_|fb)G+{
} <45dy5!Tz
} 2K7:gd8Ru
aN);P>
]oZ,{Q5~
/* CSg5i&A=
**Utility.java m{=~|I
*/ :!it7vZ
package NetFox; +^% &8<
1'._SMP
*Uw#
public class Utility { 5]O LV1Xt
zdQu%q
=v#A&IPA'
public Utility() J$=b&$I(
{ l8 2uK"M
V%KW[v<G<
Gpp}Jpj
} 22(]x}`
~a0}
//线程睡眠 d'@H@
public static void sleep(int nSecond) #(wzl
{ #Ew eG^!#
try{ ?+JxQlVDt-
Thread.sleep(nSecond); EO!cv,[a
} Js2_&?}3f
catch(Exception e) ~}9H<K3V
{ KV&_^xSoh|
e.printStackTrace (); v lnUN
} $;j6*,H
} LYo7?rp
oDiv9jm
//日志 lNp:2P
public static void log(String sMsg) kQiW5
{ ^=M(K''
System.err.println(sMsg); \(7#N<-
} g&(~MD2{
c3 ]^f6)?
dZ81\jdYv
public static void log(int sMsg) hI#M {cz
{ 5^qp&
System.err.println(sMsg); ^ cd5Zl
} \\pyu]z
} (Y@|h%1W
f(ec/0W
F$.s6Hh.
/* ENF@6]
**TestMethod.java 6!L*q
*/ )o(F*v
package NetFox; |N3CoB
g,]5&C T3v
-VT?/=Y s
public class TestMethod { zpQ/E
jc.Uh9Kc
s 17gi,"X
public TestMethod() Dve5m=
{ ///xx/weblogic60b2_win.exe I6Q_A
try{ R$,iDv.jI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c15^<6]g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5|={1Lp24g
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9 7qS.Z27
fileFetch.start(); 'cc4Y~0s
} +}Wo=R}
catch(Exception e){e.printStackTrace ();} yXQ;LQ;
nU#q@p)Xg
Qvg"5_26v
} "TNUw&ih
.T>}O0L"
J]YN2{(x
public static void main(String[] args) PSw+E';
{ <Q~7a hF
new TestMethod(); xa^HU~
} q`K-T_<
} ?{Z0g+B1
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