http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); e1:u1(".
} v4X_v!CQ
for(int i=0;i<nEndPos.length-1;i++) _QD/!~O
{ yIM.j;5:~5
nEndPos = nStartPos[i+1]; [))gn
} aS3P(s L
nEndPos[nEndPos.length-1] = nFileLength; >9<_s ^_
} 6R0D3kW
} ojiM2QT}m
YNuewD
:t_}_!~
//启动子线程 ;D6x=v=2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @2QJm
for(int i=0;i<nStartPos.length;i++) f|;HS!$
{ %{7$\|;J'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QxP` fKC8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oBhL}r
nStartPos,nEndPos,i); 6(!,H<bON
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GZ;Z
fileSplitterFetch.start(); <m-Ni
} hB?U5J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *'kC8ZR5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H0 {Mlu9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bWhJ^LD
nEndPos = " + nFileLength); bkJwPs
// fileSplitterFetch[nPos.length-1].start(); hhN(;.
:-W$PIBe
clij|?O
//等待子线程结束 8 ))I$+
//int count = 0; zS&7[:IRs'
//是否结束while循环 =>E44v
boolean breakWhile = false; 2 rbX8Y
qpH j4
/&y,vkZTT
while(!bStop) @^w!% ?J
{ n=lggBRx
write_nPos(); c80"8r
Utility.sleep(500); 11nO<WH
breakWhile = true; C@l +\M(
Zw3hp,P]
s|Imz<IE
for(int i=0;i<nStartPos.length;i++) {X{01j};8
{ %Z-TbOX
if(!fileSplitterFetch.bDownOver) e7)>U!9c9
{ z:@d@\$?
breakWhile = false; +]aD^N9['
break; VQZT.^
} bQ${8ZO
} +_vm\]4
if(breakWhile) pO-)x:Wg
break; gDUoc*+h
J tn&o"C
o(S^1j5
//count++; ee__3>H"/
//if(count>4) rd f85%%7
// siteStop(); ?j},O=JFn
} _rWTw+ L
(7 ]\p
AmUe0CQ:k'
System.err.println("文件下载结束！"); K6PC&+x
} 8trm`?>
catch(Exception e){e.printStackTrace ();} bCe[nmE2
} oW\Q>c7 =
x3:ZB
#,Fx@3y\a
//获得文件长度 Lx4H/[$6D
public long getFileSize() l,~ N~?
{ o =jX
int nFileLength = -1; 5VY%o8xXa
try{ zmrX%!CW
URL url = new URL(siteInfoBean.getSSiteURL()); Y6[]wUJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HzFt
httpConnection.setRequestProperty("User-Agent","NetFox"); m-&a~l
(RI>aDGRH
Lt#:R\;&
int responseCode=httpConnection.getResponseCode(); }K qw\]`
if(responseCode>=400) A=@V LU4%
{ }VJ hw*s
processErrorCode(responseCode); Ezo" f
return -2; //-2 represent access is error 3 8ls 4v3
} "X!_37kQ
-&HoR!af
~h~r]tV*+
String sHeader; ZFd{q)qe
g tSHy*3]
g]TI8&tP!L
for(int i=1;;i++) 42H#n]Y
{ [jG uO%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dnhpWVhn
//Utility.log(in.readLine()); f{oxF?|89
sHeader=httpConnection.getHeaderFieldKey(i); hyr5D9d
if(sHeader!=null) _^,[wD
{ LXOF{FG
if(sHeader.equals("Content-Length")) +eVpMD( l
{ `cy"-CJS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~>wq;T:=
break; +O%a:d%
} Qr xO erp
} 0v,`P4_k
else >LRaIU>
break; `;8u9Ff
} pQ6t]DJ4
} U7Sl@-#|
catch(IOException e){e.printStackTrace ();} %.r5E2'
catch(Exception e){e.printStackTrace ();} itvy[b-*
kk>0XPk
".7KEnx
Utility.log(nFileLength); <=LsloI
8~XI7g'5x
{pi67"mYp
return nFileLength; +HVG5l
} wNlV_
[~rk`
(Nve5
//保存下载信息（文件指针位置） E].a|4sh
private void write_nPos() 6CzvRvA*P
{ ,J4a~fPf
try{ vU=k8
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7dL=E"WL
output.writeInt(nStartPos.length); ~(L<uFU V
for(int i=0;i<nStartPos.length;i++) Fb`7aFIf
{ aWi]t'_
// output.writeLong(nPos); {/Q?
output.writeLong(fileSplitterFetch.nStartPos); ob()+p.kK
output.writeLong(fileSplitterFetch.nEndPos); OAQ O J'
} N"Nd$4
output.close(); aABE= 9Y
} we@En .>f
catch(IOException e){e.printStackTrace ();} (Su2\x
catch(Exception e){e.printStackTrace ();} ?&t|?@
} M<me\s)
Y3F.hk}O
41_sSqq;^
//读取保存的下载信息（文件指针位置） Tx&qp#FS
private void read_nPos() K,T]Fuy
{ X+G*Q}5
try{ nCmrt*&}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d~oWu [F*
int nCount = input.readInt(); Ns] 9-D
nStartPos = new long[nCount]; bJ5z??
nEndPos = new long[nCount]; FWx*&y~$
for(int i=0;i<nStartPos.length;i++) bTYP{x~ y
{ 0GLB3I >
nStartPos = input.readLong(); b`%e{99\
nEndPos = input.readLong(); Xf/<.5A
} 7|?@\ZE
input.close(); [,V92-s;N
} $/sZYsN~T
catch(IOException e){e.printStackTrace ();} Q\th8/ /
catch(Exception e){e.printStackTrace ();} 'm.XmVZL%
} ? Gu_UW
_O71r}4
2ZFKjj
private void processErrorCode(int nErrorCode) o\Vt $
{ p[+me o
System.err.println("Error Code : " + nErrorCode); G6g=F+X2
} "I1M$^8n
d}G."wnG9,
At_Y$N:
//停止文件下载 s)ajy^6'M
public void siteStop() RwLdV+2\R`
{ ^oZs&+z
bStop = true; L,ey3i7a\
for(int i=0;i<nStartPos.length;i++) 61;5Yo
fileSplitterFetch.splitterStop(); Wn</",Gf
0BZOr-i
#~qp8 w
} U@ QU8
} -D':7!@
//负责部分文件的抓取 9fLP&v
**FileSplitterFetch.java h 7P?n.K
*/ [~%;E[ky$
package NetFox; V$%Fs{
?;QKe0I^
=1B&d[3;
import java.io.*; :jp$X|
import java.net.*; "S} hcAL/
5m;wMW<
w)c#ZJHG
public class FileSplitterFetch extends Thread { K>~cY%3^i
,#FH8%Yf
tQ<2K*3]
String sURL; //File URL Ji?UG@
long nStartPos; //File Snippet Start Position 4o8HEq!
long nEndPos; //File Snippet End Position M L_J<|,J
int nThreadID; //Thread's ID ;SP3nU))
boolean bDownOver = false; //Downing is over ZQ8Aak
boolean bStop = false; //Stop identical Y2$`o4*3
FileAccessI fileAccessI = null; //File Access interface g5HqU2
`6F8Kqltr
oU6g5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~Q\uP(!D
{ { J%$.D(/
this.sURL = sURL; f3&//h8
this.nStartPos = nStart; +f~3FXM
this.nEndPos = nEnd; ^]K)V
nThreadID = id; zL{@LHP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @"5u~o')@v
} ^IZ0M1&W;
s8O+&^(U
WkmS
public void run() ,;& PKY
{ 90I3_[Ii
while(nStartPos < nEndPos && !bStop) p;01a
{ t`D@bzLC%
f}uCiV!?v
"qp_*Y
try{ tHo/uW_~I
URL url = new URL(sURL); (G;*B<|A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R-|]GqS}L
httpConnection.setRequestProperty("User-Agent","NetFox"); P"VLGa
String sProperty = "bytes="+nStartPos+"-"; )y Y;%
httpConnection.setRequestProperty("RANGE",sProperty); a"N_zGf2$
Utility.log(sProperty); 2UJ0%k
: \`MrI^
Nd)o1{I
InputStream input = httpConnection.getInputStream(); ?*dx=UI
//logResponseHead(httpConnection); ps J 1J
j>M%?Tw
XV!EjD~q
byte[] b = new byte[1024]; j<5R$^?U
int nRead; $dUN+9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c9k,Dc
{ B75SLK:h=
nStartPos += fileAccessI.write(b,0,nRead); c9={~
//if(nThreadID == 1) v2g+oKO]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tr+~@]I+
} {1ceF
(9%%^s]uPT
0:S)2"I58p
Utility.log("Thread " + nThreadID + " is over!"); j+_75t`AZ
bDownOver = true; *mtv[
//nPos = fileAccessI.write (b,0,nRead); r4zS,J;,
} GT0'bge
catch(Exception e){e.printStackTrace ();} (q7mzZY
} )9,"~P2[R
} Hn.UJ4V
yh!vl&8M
-|mRJVl8
//打印回应的头信息 [G)Sq;
public void logResponseHead(HttpURLConnection con) #d(r^U#I
{ ;I'["k%
for(int i=1;;i++) /y@iaptC
{ ,B!Qv3bn
String header=con.getHeaderFieldKey(i); Ss}0.5Bq
if(header!=null) b@Cvs4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8tk`1E8!j
Utility.log(header+" : "+con.getHeaderField(header)); i>}z$'X
else )I9(WVx!]
break; }(6k7{,Gw,
} .? /J
} zvj\n9H
HB:i0m2fJW
!9NAm?Fw
public void splitterStop() F*H}5yBp_:
{ R~([
bStop = true; C]cw@:o%
} >i<-rO>kN
9x\G(w
@TDcj~oR?
} FT=>haN
3dLz=.=)'
v8[1E>&vx
/* $%'z/'o!
**FileAccess.java ^DOcw@Z6HC
*//文件访问(定位，写) FW,D\51pTP
package NetFox; v2Y=vr
import java.io.*; .S;/v--F
1g+<`1=KT
wr(?L7 $+
public class FileAccessI implements Serializable{ |Rc#Q<Vh|
0XNb@ogo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &2J|v#$F
RandomAccessFile oSavedFile; 5[k35c{
long nPos; ,8seoX^
ai RNd~\
~r3g~MCHS
public FileAccessI() throws IOException E%N]t} }[
{ 98"NUT
this("",0); QkbN2mFv%
} !/SFEL@_B
;iVyJZI
Sz&`=x#
public FileAccessI(String sName,long nPos) throws IOException cA kw5}P
{ 4(]k=c1<
oSavedFile = new RandomAccessFile(sName,"rw"); ikC;N5Sw
this.nPos = nPos; fx},.P=:*
oSavedFile.seek(nPos); CDhk!O..
} 5o*x?P!$
%qMk&1
iuEdm:pW
public synchronized int write(byte[] b,int nStart,int nLen) ns-x\B?^
{ %k_JLddlW
int n = -1; Nnw iH
try{ ;N|6C+y
oSavedFile.write(b,nStart,nLen); \=JKeL|6[S
n = nLen; ' BpRiN
} R0WJdW#
catch(IOException e) "d'@IN
{ >8Y >B)
e.printStackTrace (); B4C`3@a
} $Fj7'@1(
=z+zg^wsT
OB%y'mo7]
return n; fi1UUJ0 U;
} -c tZ9+LL
be_t;p`3
'JydaF~>
} !VW#hc\A5
?`xId;}J#7
Tym!7H2
/* '@FKgy;B)-
**SiteInfoBean.java sx;1V{|g
*/ y< 84Gw_
package NetFox; 5o?bF3
/dAIg1ra
YL]x>7T~4t
public class SiteInfoBean { 9ccEF6o0=
VCIG+Gz
DIY WFVh
private String sSiteURL; //Site's URL YG_3@`-<
private String sFilePath; //Saved File's Path 4s~o
private String sFileName; //Saved File's Name 01J.XfCd6
private int nSplitter; //Count of Splited Downloading File :3k(=^%G!
JW$#~"@r
BmZd,}{
public SiteInfoBean() <M=K!k
{//nSplitter的缺省值为5 $d'Gh2IGA
//default value of nSplitter is 5 rv+"=g
this("","","",5); Z`D#L[z$
} PQ j_j#0
\K=Jd#9c
&Z?uK,8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OtJS5A
{ iMSS8J
sSiteURL= sURL; #8A|-u=3
sFilePath = sPath; 6gv.n
sFileName = sName; +ad 2
this.nSplitter = nSpiltter; U;_;_
MkQSq MU=
Kxg09\5i
} rei<{woX
,,?t>|3
a}yJ$6xi
public String getSSiteURL() 'uh6?2)wG
{ %!@Dop/<
return sSiteURL; 1.+MX(w
} W];4P=/
VGSe<6Hh
G2mv6xK'
public void setSSiteURL(String value) GYBM]mW^ W
{ [bAv|;
sSiteURL = value; m2_B(-
} [p(Y|~
KjLj
'+$2<Ys
public String getSFilePath() h5~tsd}OU
{ W>Zce="_gN
return sFilePath; ?wmr~j
} |XQ!xFB
'1d-N[
P/27+5(|
public void setSFilePath(String value) !=a8^CV
{ Es?~Dd
sFilePath = value; $]O\Ryf6
} :g Ze>
&.d~ M1Mz
aFLm,
public String getSFileName() %;gD_H4mm
{ R\iU)QP
return sFileName; -IPc;`<
} 2rA`y8g(L
h4V.$e<T&
c|E
public void setSFileName(String value) k1X<jC]P
{ )+{'p0
sFileName = value; C; ! )<(Vw
} |XeuqZa
En1pz\'
7.]ZD`"Bb
public int getNSplitter() gbF.Q7?$u
{ JTVCaL3Z
return nSplitter; tL D.e
} *F=wMWa
2Ddrxc>48
J6jrtLh
public void setNSplitter(int nCount) X_XqT
{ T1Xm^{
nSplitter = nCount; k)4
} ~dC^|
} )5B90[M|t
) ~X\W\
pmfyvkLS
/* C0'Tua'
**Utility.java GMFp,Df
*/ y>|7'M*+
package NetFox; &}rh+z
^G15]Pyw
6zyozJA
public class Utility { I9_tD@s"(
)PZ'{S
e KET8v[
public Utility() 0?k/vV4
{ JrO2"S
*2@Ne[dYEF
g!4"3Dtdg
} \ B<(9
lepgmQ|oY
//线程睡眠 R(3V !ph
public static void sleep(int nSecond) U1B5gjN
{ %T!UEl`v
try{ "#(]{MY
Thread.sleep(nSecond); RoPz?,u
} Yk[yG;W
catch(Exception e) 9;kWuP>k4u
{ 'R= r9_%
e.printStackTrace (); -]HO8}-Rjs
} !<@Zf4m
} 6:J @
jRzR`>5
//日志 .BZw7 YV
public static void log(String sMsg) (1*?2u*j
{ v@[MX- ,8
System.err.println(sMsg); TR|G4l?
} % `\8z
J7$5<
RytQNwv3
public static void log(int sMsg) qd"*Td
{ P5kkaLzG
System.err.println(sMsg); q f-1}
} (V}DPA
} "@DCQ
W.{#Pg1Da
HX?5O$<<N
/* EPW Iu)A
**TestMethod.java b>?X8)f2e
*/ WnU"&XZ
package NetFox; Q lql(*
>PfYHO
DM"`If%3j
public class TestMethod { sLPFeibof5
D:M0_4S
|{<g-)
public TestMethod() q#F;GD
{ ///xx/weblogic60b2_win.exe %mg |kb6n
try{ =D<46T=(RB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "3W!p+W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P8piXG
SiteFileFetch fileFetch = new SiteFileFetch(bean); PKty'}KF
fileFetch.start(); 3@_je)s
} Jcy
catch(Exception e){e.printStackTrace ();} Jx(%t<2
Q];+?Pu.
UeX3cD
} kL{2az3"c
D\bW' k]!
i` n,{{x&4
public static void main(String[] args) rV54-K;`0
{ pu=Q;E_f[
new TestMethod(); 32:q'
} 8it|yK.G@&
} M n3cIGL
点击下载更多相关资料