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)); flC%<V%'-
} =&pLlG
for(int i=0;i<nEndPos.length-1;i++) 6hd<ys?
{ 3+uL@LXd
nEndPos = nStartPos[i+1]; *-Yw%uR
} T_D] rMl
nEndPos[nEndPos.length-1] = nFileLength; =$)M-;6
} \$.{*f
} LFW`ISY{
N%Ta.`r
%c\kLSe
//启动子线程 *5k40?w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]OdZlZBsJ
for(int i=0;i<nStartPos.length;i++) 4c(Em+4
{ I-g/)2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $F# 5/gDVQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7mdd}L^h Z
nStartPos,nEndPos,i); 8Vj'&UY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7p2xst
fileSplitterFetch.start(); I_z(ft.
} TbNH{w|p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MaHP):~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;9h;oB@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %EVgSF!r
nEndPos = " + nFileLength); D@68_sn
// fileSplitterFetch[nPos.length-1].start(); O8bxd6xb
KfBT'6t
=HsE:@
//等待子线程结束 Q*%}w_D6f
//int count = 0; kUS]g r~i
//是否结束while循环 `q<W %'Tb$
boolean breakWhile = false; U7D!w$4
&5R|{',(Y
'n,V*9
while(!bStop) bz#]>RD
{ =iKl<CqI$E
write_nPos(); cXqYO|3/M
Utility.sleep(500); C[ mTVxd
breakWhile = true; KsOWTq"uj
P* `*^r3
1,;X4/*
for(int i=0;i<nStartPos.length;i++) p+V#86(3
{ J,CwC)
if(!fileSplitterFetch.bDownOver) \|{/.R
{ rfEWh Vy(}
breakWhile = false; f!#!
break; %Rn*oV
} S=mqxIo@m
} lh"*$.j-
if(breakWhile) c'eZ-\d{
break; _;;Zz&c
%;dj6):@
(XVBH1p"
//count++; oXnaL)Rk
//if(count>4) eyyME c!
// siteStop(); esnq/
} 6ABK)m-y
w(6n
X^ Is-[OvE
System.err.println("文件下载结束！"); V9v20iX
} XhM!pSl\
catch(Exception e){e.printStackTrace ();} pzz*>Y
} 87 s*lS
gk%@& TB/
rYr*D[m]
//获得文件长度 |M?vFF]TN
public long getFileSize() b[<RcM{r}
{ ~.%HZzR6&
int nFileLength = -1; @GFB{ ;=
try{ Y"MHs0O5>
URL url = new URL(siteInfoBean.getSSiteURL()); l,4O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~x9]?T
httpConnection.setRequestProperty("User-Agent","NetFox"); zd=O;T;.
?qaWt/m
>SK:b/i
int responseCode=httpConnection.getResponseCode(); ]h,rgO;
if(responseCode>=400) L\PmT
{ clB K
processErrorCode(responseCode); ccHf+=
return -2; //-2 represent access is error zOs}v{8"
} ">oySo.B?
3O/#^~\'hW
l&qnqmW<
String sHeader; y'K2#Y~1e
Z]]Ur
!,m
for(int i=1;;i++) CP~ZIIip"
{ \x}\)m_7M<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cgMF?;V
//Utility.log(in.readLine()); sF{aG6u
sHeader=httpConnection.getHeaderFieldKey(i); X@\W* nq
if(sHeader!=null) DpT9"?g7
{ g|>LT_
if(sHeader.equals("Content-Length")) 'k X8}bx
{ H&)}Z6C"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +P2oQ_Fk`9
break; !5o j~H
} e|\xFV=4
} IW0S*mO$
else i7Up AHd/
break; }uZs)UQ|$
} y QW7ng7D0
} \l~^dn}
catch(IOException e){e.printStackTrace ();} RRIh;HhX
catch(Exception e){e.printStackTrace ();} |vI`u[P
SeD}H=,@
-&5YRfr!
Utility.log(nFileLength); aTuu",f
-fq
e7RgA1
return nFileLength; K*>%,mP$i
} VVas>/0qr
5qb93E"C
{]T?)!Vm
//保存下载信息（文件指针位置） @Vre)OrN#
private void write_nPos() 0<uek
{ Ek_5% n
try{ y7,I10:D
output = new DataOutputStream(new FileOutputStream(tmpFile)); =SfNA F
output.writeInt(nStartPos.length); s<s}6|Z
for(int i=0;i<nStartPos.length;i++) 8=`L#FkRp
{ )L:zr#
// output.writeLong(nPos); [IL*}M!
output.writeLong(fileSplitterFetch.nStartPos); 0[MYQl`
output.writeLong(fileSplitterFetch.nEndPos); Jb QK$[z"
} ZZY#.
output.close(); K~TwyB-h
} e&}W#
catch(IOException e){e.printStackTrace ();} C^J<qq&
catch(Exception e){e.printStackTrace ();} Lx0nLJ\
} cS;3,#$
SVe]2ONd
9TW[;P2> )
//读取保存的下载信息（文件指针位置） D=0YLQ*rP
private void read_nPos() O3} JOv_
{ EwC]%BZP
try{ .XJ'2yKof
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yLnQ9BXB&
int nCount = input.readInt(); XX8HSw!w
nStartPos = new long[nCount]; 3uLG$`N
nEndPos = new long[nCount]; q+?<cjVg
for(int i=0;i<nStartPos.length;i++) VdlT+'HF
{ P.Z:`P)
nStartPos = input.readLong(); paqGW]
nEndPos = input.readLong(); *N">93:
} =;rLv7(a
input.close(); SqM>xm
} \^!;r9z=A
catch(IOException e){e.printStackTrace ();} mZ+!8$1X
catch(Exception e){e.printStackTrace ();} I/O3OD
} FK _ ZE>
mUBy*.
2q~.,vpP
private void processErrorCode(int nErrorCode) \SWTP1
{ *uc/| c
System.err.println("Error Code : " + nErrorCode); IO\l8G
} ^A$=6=CX
DrJ?bG;[
d:%b
//停止文件下载 K./qu^+k
public void siteStop() ;TAj;Tf]H
{ \|HEe{nA
bStop = true; *~#I5s\s!
for(int i=0;i<nStartPos.length;i++) my (@~'
fileSplitterFetch.splitterStop(); QAs)zl0
fAsb:P
U,Z\)+-R
} J @Hg7Faz
} 6'^_*n
//负责部分文件的抓取 9@ k8$@
**FileSplitterFetch.java &dyQ6i$],
*/ vqm|D&HU
package NetFox; vpQ&vJfR
/ZvP.VW&
scg&"s
import java.io.*; V]7/hN-Y}
import java.net.*; B7%K}|Qg
.shi?aWm
:zY4phR
public class FileSplitterFetch extends Thread { 2"IV
8y LcTA$T
Q:A#4Z
String sURL; //File URL nLN0zfhE#
long nStartPos; //File Snippet Start Position HpnF,4A>
long nEndPos; //File Snippet End Position )w7vE\n3
int nThreadID; //Thread's ID q$:1Xkl
boolean bDownOver = false; //Downing is over RkYdK$|K
boolean bStop = false; //Stop identical Y%KowgP\
FileAccessI fileAccessI = null; //File Access interface `"5Ub,~
+A}t_u3<
fap`;AuwK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r w?wi}}gn
{ $L*gtZ
this.sURL = sURL; q0.!T0i
this.nStartPos = nStart; IZZAR
this.nEndPos = nEnd; ^'`b\$km-0
nThreadID = id; )|~K&qn`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x~e._k=
} 5X{|*?>T
I dK*IA4
\Zj%eW!m
public void run() H*=cw<
{ }z`x-(V
while(nStartPos < nEndPos && !bStop) hb`9Vn\-E
{ \|PiQy*_?
Z@bgJL83
-CvmZ:n
try{ m Q2i$ 0u
URL url = new URL(sURL); <V?2;Gy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _2fW/U54_
httpConnection.setRequestProperty("User-Agent","NetFox"); ..N6]u
String sProperty = "bytes="+nStartPos+"-"; iLy^U*yK
httpConnection.setRequestProperty("RANGE",sProperty); s= Fp[>qA
Utility.log(sProperty); F9%_@n
R{g= N%O
;K<VT\
InputStream input = httpConnection.getInputStream(); wm5&5F4:
//logResponseHead(httpConnection); I}`pY3
)N.3Q1g-
0L}`fYf
byte[] b = new byte[1024]; TU|#Pz7n-Z
int nRead; ,GSiSn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +( LH!\{^
{ #-L0.z(
nStartPos += fileAccessI.write(b,0,nRead); &~:EmLgv
//if(nThreadID == 1) de:@/-|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f"Sp.'@
} KuR]X``2
Y@FYo>0O
l2F#^=tp
Utility.log("Thread " + nThreadID + " is over!"); E !kN h
bDownOver = true; '2^}de!E
//nPos = fileAccessI.write (b,0,nRead); Phn^0 iF
} ;Q{D]4
catch(Exception e){e.printStackTrace ();} a\P:jgF
} +XWTu!
} ?_eLrz4>L^
|"*P`C=
>|3Y+X
//打印回应的头信息 LUQ.=:mBR
public void logResponseHead(HttpURLConnection con) od `;XVG
{ 7KgaXi3r
for(int i=1;;i++) EQyX!
{ nCYz];".
String header=con.getHeaderFieldKey(i); ~XR('}5D
if(header!=null) |lNp0b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 72l:[5ccR
Utility.log(header+" : "+con.getHeaderField(header)); }a"=K%b<\
else qiz(k:\o
break; K|%Am4
} ^G!cv
} mV}bQ^*?Z
}?2X q
^Mq/Cf_T
public void splitterStop() mm>l:M TF
{ GCl *x:
bStop = true; Q>5f@aN
} AXbb-GK
tddwnpnSw
Z_GGH2u
} ct\msG }b:
T@1;Nbz]
e66Ag}Sw|
/* .$\-{)
**FileAccess.java 2J=`"6c
*//文件访问(定位，写) =%` s-[5b
package NetFox; xP\s^]e
import java.io.*; #$UwJB]_D
onuG
jf)cDj2
public class FileAccessI implements Serializable{ ^\PRzY
?NA$<0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P%R!\i
RandomAccessFile oSavedFile; ?s,oH
long nPos; @|A!?}
Sh#N5kgD
1uw1(iL+
public FileAccessI() throws IOException .=:f]fs
{ W3~u J(
this("",0); cW^LmA
} ^_#wo"
YeCnk:_ kg
.]E(P
public FileAccessI(String sName,long nPos) throws IOException .u mqyU~
{ `R0~mx&6G
oSavedFile = new RandomAccessFile(sName,"rw"); k<*v6 sNs;
this.nPos = nPos; JWHsTnB
oSavedFile.seek(nPos); #`y[75<n
} dOv\]
DOyO`TJi
sqhMnDn[
public synchronized int write(byte[] b,int nStart,int nLen) QtfL'su:
{ [pU(z'caS
int n = -1; -W!M:8
try{ *Xnf}Ozx
oSavedFile.write(b,nStart,nLen); ?=lb@U
n = nLen; U-DQ?OtmC@
} +E. D:
catch(IOException e) bIm4s
{ 4L>8RiiQE;
e.printStackTrace (); e!J5h<:
} ^?{&v19m
B-g-T>8
4- QlIIf
return n; }`CF(Do
} )ThNy:4
C9+rrc@4
(-yif&
} "]jN'N(.
G+#bO5
tD`^qMua
/* }Bv1fbD4U
**SiteInfoBean.java xD*Zcw(vj~
*/ oL9<Fi
package NetFox; E 14DZ
r.)n>
yLf9cS6=
public class SiteInfoBean { !RJ@;S
ItLR|LO9
l!}gWd,H
private String sSiteURL; //Site's URL AyQ5jkIE^{
private String sFilePath; //Saved File's Path vRtERFL
private String sFileName; //Saved File's Name yW?-Z[
private int nSplitter; //Count of Splited Downloading File MgP|'H3\
B^9C}QB
Sm[#L`eqW
public SiteInfoBean() F3V:B.C
{//nSplitter的缺省值为5 I]n X6=j5
//default value of nSplitter is 5 hpQ #`rhn
this("","","",5); 1q;R+65
} 6 wd
'{0O!y[H6
P'iX?+*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g@x72$j
{ vE`;1UA}
sSiteURL= sURL; cFie;k
sFilePath = sPath; j)G%I y[`
sFileName = sName; m\*ca3$
this.nSplitter = nSpiltter; H,<CR9@(5d
7kD?xHpe
>/Z*\6|Zx#
} I!Dx)>E&
8\E=p+C
R6X2d\l#
public String getSSiteURL() 8m H6?,@6
{ +Y*4/w[
return sSiteURL; =mQY%l
} b&A/S$*
wx-&(f
+)h# !/
public void setSSiteURL(String value) zEQQ4)mA
{ xBc$qjV
sSiteURL = value; 2.JrLBhN
} %o/@0.w
O.#Rr/+)
KUPQ6v }
public String getSFilePath() |H=5Am
{ n[y=DdiKGS
return sFilePath; ?lqqu#;8
} &OFVqm^
?0u"No52m
5O~xj:
public void setSFilePath(String value) I;AS.y
{ ^x*J4jl
sFilePath = value; :9&@/{W
} sAO/yG
wqm{f~nj=
Z OAg7
public String getSFileName() fWJOP sp*/
{ g<~ODMCO?W
return sFileName; 9*JxP%8T~X
} fFC9:9<
aiX4;'$x!
f dJg7r*
public void setSFileName(String value) LDw.2E
{ -A}$5/
sFileName = value; 2N-p97"g
} k^JgCC+
G@e;ms1
EhD%
public int getNSplitter() h`Ej>O7m
{ =|O]X|y-lZ
return nSplitter; >yenuqIKQv
} #mioT",bm=
b+RU <qR
eJ[+3Wh
public void setNSplitter(int nCount) IY~I=}
{ }|-8-;
nSplitter = nCount; B~Z61
} j AoI`J
} J#w=Z>oz<
`{yD\qDyX
= ?/6hB=7<
/* e?XGv0^qu
**Utility.java 7"eIZ
*/ kVeY} 8
package NetFox; %;_EWs/z8
i5WO)9Us
x`p908S^
public class Utility { -NzOX"V]3
^755LW
@VND}{j
public Utility() 1*#hIuoj'
{ mWoN\Rwj
)abH//Pps.
&a >UVs?=
} yWN'va1+$
5^qs>k[mN
//线程睡眠 S=L#8CID
public static void sleep(int nSecond) BB/c5?V
{ LEg|R+6E
try{ &RS)U72
Thread.sleep(nSecond); ndBqXS
} *!NW!,R
catch(Exception e) $Zi{1w
{ >Ir?)h
e.printStackTrace (); gpbdK?
} MD0d
} INCanE`+
!t)uRJ
//日志 {)Zz4
public static void log(String sMsg) g p9;I*!
{ a*,V\l|6
System.err.println(sMsg); 2*-qEUl1
} :E|+[}|
RLw/~
;8]Hw a1!
public static void log(int sMsg) vl`St$$|
{ \WUCm.w6\%
System.err.println(sMsg); )>rYp )
} W"~"R
} H]dN'c-
K(NP%:
za.^vwkBk2
/* rd(-2,$4
**TestMethod.java $0M7P5]N*G
*/ |f}`uF
package NetFox; +miL naO~L
'7]9q#{su
5"x1Pln
public class TestMethod { >G0ihhVt
1 !.PH
I=E\=UTG,5
public TestMethod() ;$r!eFY;
{ ///xx/weblogic60b2_win.exe Nw1 .x
try{ U|+`Eth8(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hz2f7g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z 2uU'T
SiteFileFetch fileFetch = new SiteFileFetch(bean); Hw#yw g
fileFetch.start(); Yk7^?W
} =lh&oPc1
catch(Exception e){e.printStackTrace ();} JS >"j d#
~W gO{@Mw
r_V^sX
} Ys5Iqj=mp
gFM~M(
YL4yT`*
public static void main(String[] args) ?I.bC
{ 57N<OQWf
new TestMethod(); @<1T&X{Z!
} ?`SBGN;
} y0t-e
点击下载更多相关资料