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)); BhMHT:m
} W1@Q)i
for(int i=0;i<nEndPos.length-1;i++) 9hG+?
{ YBX7WZCR
nEndPos = nStartPos[i+1]; i"rrM1/r
} !`VO#_TJ
nEndPos[nEndPos.length-1] = nFileLength; &M,"%w!
} BBg&ZIYEh
} C~5-E{i
E9Q?@'h
MKuy?mri~
//启动子线程 GW(-'V/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q)l]TgvSe
for(int i=0;i<nStartPos.length;i++) ^z[-pTY
{ LX %8a^?;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xYMNyj~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JMMsOA_]
nStartPos,nEndPos,i); J{Z-4y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zn |=Q$81
fileSplitterFetch.start(); C+WHg-l
} ; md{T'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9u'hCi(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3,K*r"=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F7(~v2|
nEndPos = " + nFileLength); lRn6Zh
// fileSplitterFetch[nPos.length-1].start(); J-W,^%
GQ-owH]
6g ,U+~
//等待子线程结束 $Xlyc.8YId
//int count = 0; r|Y|uv0
//是否结束while循环 tk^1Ga3
boolean breakWhile = false; VD\pQ.=
h>Z$ n`T
oE&Zf/
while(!bStop) y\ nR0m
{ ZSuMQ32
write_nPos(); 3q:-98DT
Utility.sleep(500); ifu"e_^
breakWhile = true; l|-TGjsX
X7sWu{n
tPS.r.0#^
for(int i=0;i<nStartPos.length;i++) ksxacRA7\
{ `p&ko$i2
if(!fileSplitterFetch.bDownOver) Ne]/ sQ0
{ ;y#6Nx,:
breakWhile = false; 6TE RQ
break; ?l_>rSly5
} b'$j* N
} ? OBe!NDf
if(breakWhile) eiZv|?^0
break; AJrwl^lm
F<?e79},`
N(?yOB4gt
//count++; GLb}_-|
//if(count>4) h^P>pI~
// siteStop(); %PG::b
} *@Z/L26s;=
`4cs.ab
r'hr'wZ
System.err.println("文件下载结束！"); #R|M(Z">q
} laM0W5
catch(Exception e){e.printStackTrace ();} g1\4Jb
} RB_7S!qC5
gKg2Ntxj
8w|j Z@
//获得文件长度 G'( %8\
public long getFileSize() 6|#^4D)
{ pBt/vSad
int nFileLength = -1; \n850PS
try{ @A6\v+ih
URL url = new URL(siteInfoBean.getSSiteURL()); (Jfi 3 m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v&(X&q
httpConnection.setRequestProperty("User-Agent","NetFox"); 2 G_*Pqc
a#1LGH7E8
qH6DZ|
int responseCode=httpConnection.getResponseCode(); QEM")(
if(responseCode>=400) yXNE2K
{ pFSVSSQRV|
processErrorCode(responseCode); <Ebkb3_
return -2; //-2 represent access is error hQBeM7$F_
} 0$,Ag;"^?
Be2@9
Ms(;B*
String sHeader; kq:,}fc;B
9B'l+nP
b]s=Uv#)
for(int i=1;;i++) mW 5L;>
{ w;' F;j~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %_1~z[Dv
//Utility.log(in.readLine()); /-$`GT?l
sHeader=httpConnection.getHeaderFieldKey(i); Fm-W@
if(sHeader!=null) 3h"; 2
{ -3VxjycY
if(sHeader.equals("Content-Length")) | qHWM
{ $BE^'5G&4Y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8N6a=[fv<
break; ^lu)'z%6
} AnPm5i.
} /[[zAq{OA
else N)RWC7th{
break; 9Pd~
} %@Ks<"9
} fB"3R-H?O
catch(IOException e){e.printStackTrace ();} S#+G?I3w
catch(Exception e){e.printStackTrace ();} K4n1#]8i
5]; 8
;k7` `
Utility.log(nFileLength); ]Vl5v5_
Ats"iV
v5wI?HE
return nFileLength; @D"#B@j
} q) /;|h
*8/Q_w
wXZ.D}d
//保存下载信息（文件指针位置） jXi<ZJ
private void write_nPos() ynM{hN.+H
{ gKb4n Nt
try{ ^Sy\<
output = new DataOutputStream(new FileOutputStream(tmpFile)); l$,l3
output.writeInt(nStartPos.length); 2t[c^J
for(int i=0;i<nStartPos.length;i++) g,y`[dr
{ 9qXHdpb#g"
// output.writeLong(nPos); M=o,Sav5*
output.writeLong(fileSplitterFetch.nStartPos); 1a4QWGpq
output.writeLong(fileSplitterFetch.nEndPos); +@%9pbM"z
} V.Xz n
output.close(); rxa"ji!)
} v_c'npC
catch(IOException e){e.printStackTrace ();} ![abDT5![
catch(Exception e){e.printStackTrace ();} {,APZ`q|
} c#"\&~. P
N>ct`a)BD/
w,3`Xq@
//读取保存的下载信息（文件指针位置） -#gb {vj
private void read_nPos() ZFW}Vnl
{ >w j7Y`
try{ nQ$N(2<Fe
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i'e^[oZ
int nCount = input.readInt(); ;\<?LTp/r
nStartPos = new long[nCount]; $Q{1^
nEndPos = new long[nCount]; 0M8JE9 Kx
for(int i=0;i<nStartPos.length;i++) K:y q^T7
{ j&T/.]dX&
nStartPos = input.readLong(); N8D'<BUC
nEndPos = input.readLong(); QwT]| 6>
} qZ\zsOnp
input.close(); "mPa>`?
} Go`omh b
catch(IOException e){e.printStackTrace ();} o4~ft!>
catch(Exception e){e.printStackTrace ();} 3sp*.dk
} {f^30Fw
)7j"OE
E 3I'3
private void processErrorCode(int nErrorCode) n;Iey[7_E`
{ ['s_qCA[
System.err.println("Error Code : " + nErrorCode); G~B V^
} >P0AGZ
]NFDE-Jz]
Gzp)OHgJ
//停止文件下载 ]LSa(7>EU
public void siteStop() 3gabk/
{ JyB>,t)
bStop = true; Q.yKbO<[
for(int i=0;i<nStartPos.length;i++) 2OT6*+D
fileSplitterFetch.splitterStop(); akCl05YW
M;iaNL(
*|E@81s#
} [qZ4+xF,,
} s}z,{Y$-t
//负责部分文件的抓取 X!2|_
**FileSplitterFetch.java }SN'*w@E
*/ oTa! F;I
package NetFox; gA[M
+] 5a(/m.~
_r8AO>
import java.io.*; \clWrK
import java.net.*; so8-e
23OVy^b
aSF&^/j
public class FileSplitterFetch extends Thread { 6op\g].P
RDqC$Gu
/GeS(xzQ
String sURL; //File URL ZDDwh&h
long nStartPos; //File Snippet Start Position ,@!d%rL:4]
long nEndPos; //File Snippet End Position WX=+\`NyJ(
int nThreadID; //Thread's ID P)\f\yb
boolean bDownOver = false; //Downing is over 3\WES!
boolean bStop = false; //Stop identical ?Jr<gn^D
FileAccessI fileAccessI = null; //File Access interface X_YD[
=f|>7m.p
Q`s(T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B}FF |0<
{ 5-3gsy/Mo
this.sURL = sURL; 4[-9$ r
this.nStartPos = nStart; @'rO=(-b
this.nEndPos = nEnd; nx+& {hn(
nThreadID = id; }GC{~ SZ4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Grub1=6l
} 0iB1_)~
2?ednMoE
:_H88/?RR
public void run() X@G`AD'.M
{ -)Vj08aP
while(nStartPos < nEndPos && !bStop) ~k%\ LZ3s
{ Uy_=#&jg
$+);!?^|:
[5 V
try{ (j/O=$mJ
URL url = new URL(sURL); =@z"k'Vl`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5a~1RL
httpConnection.setRequestProperty("User-Agent","NetFox"); hf-S6PEsM
String sProperty = "bytes="+nStartPos+"-"; ,@;<u'1\G
httpConnection.setRequestProperty("RANGE",sProperty); [KKoEZ
Utility.log(sProperty); AK!G#ug
gkdjH8(2
!:8!\gE^P
InputStream input = httpConnection.getInputStream(); f,#xicSB*
//logResponseHead(httpConnection); ;1 fML,8
O?!"15
O+N-x8W{
byte[] b = new byte[1024]; dB5DJ:$W$
int nRead; >gE_?%a[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9wC; m:
{ v+G:,Tc"
nStartPos += fileAccessI.write(b,0,nRead); 2$91+N*w9
//if(nThreadID == 1) &g!/@*[Nhh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y ^\8x^Eg
} 2&m7pcls
\abl|;fj
Q [{vU
Utility.log("Thread " + nThreadID + " is over!"); :9b RuUm
bDownOver = true; ||V:',#,W
//nPos = fileAccessI.write (b,0,nRead); 'gGB-=yvbO
} U6Ak"
catch(Exception e){e.printStackTrace ();} "ivqh{ ,
} w^gh&E
} >gl.(b25C
zTLn*?
d3GK.8y_z
//打印回应的头信息 &[kgrRF@HU
public void logResponseHead(HttpURLConnection con) ~<aB-.d
{ jvQ"cs$.
for(int i=1;;i++) )^TQedF
{ I8?[@kg5b'
String header=con.getHeaderFieldKey(i); 919g5f`
if(header!=null) l'QR2r7&.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >9`ep7
Utility.log(header+" : "+con.getHeaderField(header)); m+vEs,W.
else i7V~LO:gq
break; J|-HZ-Wk|J
} sFK<:ka
} DOeKW
y6}):|
SK52.xXJ
public void splitterStop() 4Z}{hc\J
{ ItADO'M
bStop = true; l #Q`f.
} 7h1gU
fh#_Mj+y
sE6J:m(
} \aIy68rH,
Tm\[q
OU@x1G{Cy
/* V%lGJ]ZEa
**FileAccess.java :N*T2mP
*//文件访问(定位，写) =joXP$n^
package NetFox; VU9P\|c@<
import java.io.*; Cw $^w
\F~Cbj+'Nu
P*`xiTA
public class FileAccessI implements Serializable{ -G#k/Rz6
I!gj;a?R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4/?}xD|?
RandomAccessFile oSavedFile; w9$8t9$|
long nPos; RWCS u$
.To:tN#
yPYJc
public FileAccessI() throws IOException {yMA7W7]
{ dM{~Ubb
this("",0); $3[\:+
} A(OfG&!
]31XX=
ROS"VV<
public FileAccessI(String sName,long nPos) throws IOException bs EpET
{ h6y4Ii
oSavedFile = new RandomAccessFile(sName,"rw"); AYIz;BmWy
this.nPos = nPos; BK9x`Oo2
oSavedFile.seek(nPos); FLI8r:
} < iI6@X>
3DC%I79
#Jz&9I<OKx
public synchronized int write(byte[] b,int nStart,int nLen) bDBO+qA
{ L8wcH
int n = -1; e~.?:7t
try{ 6h6?BQSE
oSavedFile.write(b,nStart,nLen); cO+Xzd;838
n = nLen; "%''k~UD4
} D%UZ'bHN*
catch(IOException e) ywynx<Wg
{ 7[v@*/W@
e.printStackTrace (); R{uJczu
} _T|H69 J
a,*p_:~i
Yz-JI=
return n; uO@3vY',n
} Ocwp]Mut&
U5CPkH1
^qGA!_
} 0T#xM(q[K
bLEATT[
3 t88AN=4
/* $@_t5?n``F
**SiteInfoBean.java 0w(T^GhZ
*/ r<X4ER
package NetFox; }PQSCl^I
XQ3*
#CA%]*l*F
public class SiteInfoBean { PB(
AwXt @!(
/MqXwUbO
private String sSiteURL; //Site's URL UM( l%
private String sFilePath; //Saved File's Path >*= =wlOB
private String sFileName; //Saved File's Name qfGtUkSSb
private int nSplitter; //Count of Splited Downloading File (#bp`Kih
i&pJg1
g+}s:9
public SiteInfoBean() [.j]V-61
{//nSplitter的缺省值为5 wD6!#t k
//default value of nSplitter is 5 FL`1yD^2
this("","","",5); yS)-&t!;
} BjyXQ9D
j!x<QNNX
dY/u<4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J1tzHa6
{ w53z*l>ek
sSiteURL= sURL; HkdN=q
sFilePath = sPath; ,2,SG/BB
sFileName = sName; qE0FgqRB
this.nSplitter = nSpiltter; df4sOqU
AhvvuN$n%
T9z4W]T
} 6Z(*cf/s
`10X5V@hP
E kBae=
public String getSSiteURL() ]-um\A4f
{ 3w/( /|0
return sSiteURL; crd|2bjp+
} $5lW)q A
=[P%_v``
~V2ajM1Z&O
public void setSSiteURL(String value) 4=Tpi`
{ .pM &jni Y
sSiteURL = value; L\b]k,Ksf
} _%wK}eH+sy
-G],H)M
gX@nPZjg
public String getSFilePath() psIkG0 &
{ Vk-W8[W 7
return sFilePath; ~reQV6oQua
} .3{[_iTM
2{t)DUs
{)B9Z I{+A
public void setSFilePath(String value) CKv&Re
{ w"cM<Ewu
sFilePath = value; 4%wq:y< )/
} $D QD$
.pZo(*
#PPR"w2g
public String getSFileName() (2z%U
{ rIeM+h7Wn
return sFileName; ;/@?6T"
} (8CCesy&
\!^i;1h0c3
m[Z6VHn
public void setSFileName(String value) uR#'lb`3
{ IQ3n@
sFileName = value; \ Y*h
} },DyU
bh6d./
>0PUWr$8
public int getNSplitter() f.||PH
{ LthGZ|>
return nSplitter; Dd| "iA
} \Yj#2ww
96c"I;\GXX
[ njx7d
public void setNSplitter(int nCount) XtCoX\da
{ %_R$K#T^,
nSplitter = nCount; *(k%MTG
} i"L}!5
} QU:EY'2
PzjaCp'
q@w{c=
/* 1g1?zk8zO
**Utility.java 4P|$LkI
*/ G%a] j
package NetFox; XVw-G }5
pd d|n2q
E;6~RM:
public class Utility { uie~'K\y
QhsMd-v
?*[\UC
public Utility() Oe/6.h?
{ vQUZVq5M
"2a$1Wmj(
0Cl,8P
} <B!'3C(P
##H;Yb
//线程睡眠 BI};"y
public static void sleep(int nSecond) `dDa}b
{ 2\VAmPG.Zs
try{ Yx5J$!Ld
Thread.sleep(nSecond); 4E2yH6l
} h40'@u^W
catch(Exception e) a mqOxb
{ {>@QJlE0
e.printStackTrace (); ! .AhzU1%Y
} %JQ~!3
} Va7c#P?
u?F (1iN=
//日志 =p]mX)I_
public static void log(String sMsg) )!e3.C|V1W
{ 9 ~~qAoD
System.err.println(sMsg); ^]6M["d/p
} ABc)2"i:*
RlrZxmPV>O
Hle\ON
public static void log(int sMsg) :r&iMb:Ra
{ wUoiXi09
System.err.println(sMsg); Q"%QQo}}
} Z?17Pu'Dp
} 0#QKVZq2>
p%F8'2)}
4U?<vby
/* U/Wrh($ #4
**TestMethod.java -/>9c-F
*/ g<$. - g
package NetFox; (?\?it-
o~#f1$|Xn
0x@A~!MoP
public class TestMethod { p* RC
icE|.[
mQ}Gh_'ps
public TestMethod() kn}zgSO
{ ///xx/weblogic60b2_win.exe {)xWD%
try{ GW3>&j_!d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xYI;V7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O|I+],
SiteFileFetch fileFetch = new SiteFileFetch(bean); $Jp~\_X
fileFetch.start(); aG(hs J)
} w9f _b3
catch(Exception e){e.printStackTrace ();} hGI+:Js6
Q".g.k
=q+R
} Z\Z,,g+WL
*YtB )6j
Q(Gyq:L=>
public static void main(String[] args) ([R")~`(l2
{ _({@B`N}
new TestMethod(); =A@>I0(7
} qZ*f%L(
} '^iUx,,ZQ
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