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)); XRi8Gpg
} m:2^=l4
for(int i=0;i<nEndPos.length-1;i++) NXrlk
{ CD~.z7,LC
nEndPos = nStartPos[i+1]; >kVz49j
} &h/Xku&0
nEndPos[nEndPos.length-1] = nFileLength; a`>B Ly5o
} U5de@Y
} DvvK^+-~
#\m<Sz5Gp#
onzxx4bax
//启动子线程 f+!(k)GWd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k9!{IScq
for(int i=0;i<nStartPos.length;i++) F JyT+
{ q_58;Bv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (!WD1w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xb8!B
nStartPos,nEndPos,i); `|q(h Ow2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~]2K^bh8&
fileSplitterFetch.start(); 5rik7a)Z]
} ?e 4/p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5\nAeP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F)eelPZ+,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4V`G,W4^J
nEndPos = " + nFileLength); G"t5nHY\.
// fileSplitterFetch[nPos.length-1].start(); a:w#s}bL
j#ab_3xH
^1];S^nD
//等待子线程结束 G 3ptx! D
//int count = 0; NgPk&niM
//是否结束while循环 bk[!8-b/a
boolean breakWhile = false; R6->t #n,
zO6oT1I
\9T7A&
while(!bStop) P*j|.63
{ 6'f;-2
write_nPos(); #H~64/
Utility.sleep(500); M\BRcz
breakWhile = true; 0g8NHkM:2a
K-Ef%a2#`
gB33?
for(int i=0;i<nStartPos.length;i++) ;$g?T~v7
{ V'gh6`v
if(!fileSplitterFetch.bDownOver) 5{,<j\#L
{ 9pfIzs su3
breakWhile = false; ECmW`#Otb)
break; Z%UP6%
} 'I;zJ`Trd
} $XH^~i;
if(breakWhile) Eu3E-K@y
break; ");a3hD
`R^gU]Z,
$6IJP\
//count++; VIf.q)_k
//if(count>4) iy.\=Cs$N
// siteStop(); &rR2,3r=
} N;%6:I./
F#E3q|Q"BS
v3>UV8c'
System.err.println("文件下载结束！"); JucY[`|JV
} y@yD5$/
catch(Exception e){e.printStackTrace ();} 8&dF
} ?a]mDx>xh
owv[M6lbD
9Mcae31
//获得文件长度 _yR^*}xJb
public long getFileSize() COlaD"Y
{ Z;"vW!%d
int nFileLength = -1; f|(M.U-
try{ 6Kz,{F@
URL url = new URL(siteInfoBean.getSSiteURL()); I]q% 2ie
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K*dCc}:`
httpConnection.setRequestProperty("User-Agent","NetFox"); \|[;Z"4l
G3v5KmT
%;!.n{X
int responseCode=httpConnection.getResponseCode(); \_fv7Fdp{
if(responseCode>=400) |y!A&d=xYn
{ V=3b&TkE
processErrorCode(responseCode); Flb&B1
return -2; //-2 represent access is error ],].zlN
} \'j|BJ~L f
%&bY]w
,hmL/K0"(5
String sHeader; &)<)^.@3G^
sDV Q#}a
V(*(F7+
for(int i=1;;i++) 93hxSRw
{ ,2ar7 5Va
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1h5 Akq
//Utility.log(in.readLine()); C7AUsYM
sHeader=httpConnection.getHeaderFieldKey(i); 5F"jkd+
if(sHeader!=null) 9N3eN
{ gQ.Sa j $
if(sHeader.equals("Content-Length")) FVBYo%Ap
{ x,Vr=FB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hpk7 Anp
break; RG`1en
} U m+8"W
} P0b7S'a4!
else $ME)#(
break; IE~ |iQ?-
} 0m ? )ROaJ
} ~Cjn7
catch(IOException e){e.printStackTrace ();} a[TMDU;(/4
catch(Exception e){e.printStackTrace ();} T[j,UkgGo
u#SWj,X
k VQ\1!
Utility.log(nFileLength); Aiea\jBv
Wm5dk9&x
rVsJ`+L
return nFileLength; <54 S
} Rx}Gz$
vr^qWn
,Y48[_ymm
//保存下载信息（文件指针位置） Du){rVY^d
private void write_nPos() sx<%2
{ %~S&AE-
try{ DlNX 3
output = new DataOutputStream(new FileOutputStream(tmpFile)); igAtRX%Qx
output.writeInt(nStartPos.length); _J[P[(ab
for(int i=0;i<nStartPos.length;i++) xkR0
{ GuL<Z1<c
// output.writeLong(nPos); >F&47Yn
output.writeLong(fileSplitterFetch.nStartPos); Sa5G.^XI
output.writeLong(fileSplitterFetch.nEndPos); )\^-2[;
} pD]OT-8
output.close(); ~u+9J}
} 5/z/>D;
catch(IOException e){e.printStackTrace ();} =nHgDrA_
catch(Exception e){e.printStackTrace ();} gPc=2
} t&DEb_"De
Ti&z1_u
8HdAFRw
//读取保存的下载信息（文件指针位置） -|\ZrE_h
private void read_nPos() ^sg,\zD 'X
{ C"enpc_C/
try{ W*w3[_"sr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WMP,\=6k0
int nCount = input.readInt(); tklH@'q
nStartPos = new long[nCount]; ^zgo#J5O
nEndPos = new long[nCount]; /H+a0`/
for(int i=0;i<nStartPos.length;i++) 'A[dCc8O
{ BFW&2
nStartPos = input.readLong(); GvlS%
nEndPos = input.readLong(); OK gqT!
} A.w:h;7
input.close(); vVcob}ZH
} ei5~&
catch(IOException e){e.printStackTrace ();} 4nz35BLr
catch(Exception e){e.printStackTrace ();} z&^&K}
} k-""_WJ~^
c6/=Gq{.
sUm'
private void processErrorCode(int nErrorCode) W+1^4::+
{ B,fo(kG
System.err.println("Error Code : " + nErrorCode); FU<Jp3<%
} W|(1Y D
.XhrCiZ
gKCX|cULY
//停止文件下载 FNId;
public void siteStop() ]jRfH(i
{ o,3a4nH;
bStop = true; 8sK9G` k
for(int i=0;i<nStartPos.length;i++) uA#;G/$
fileSplitterFetch.splitterStop(); {cw /!B
q6X1P"%.
EDs\,f}
} 5+ MS^H
} ,wdD8ZT'Ip
//负责部分文件的抓取 hwNf~3eJk
**FileSplitterFetch.java h3@v+Z<}
*/ t<?,F
package NetFox; Y:)e(c"A
B^jc3 VsR
-`TEVS?`l
import java.io.*; 9k[9P;"F:
import java.net.*; XHGFf_kW_N
LB?u8>a' I
%GIr&V4|
public class FileSplitterFetch extends Thread { `x%>8/
"Os_vlapHo
ps DetP
String sURL; //File URL u,Kly<0j
long nStartPos; //File Snippet Start Position S?BG_J6A7
long nEndPos; //File Snippet End Position 26x[X.C:
int nThreadID; //Thread's ID 1 I",L&S1
boolean bDownOver = false; //Downing is over {P#|zp4C{
boolean bStop = false; //Stop identical U\!X,a*ts{
FileAccessI fileAccessI = null; //File Access interface CQDkFQq-dq
_/<x
z,%$+)K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yyy|Pw4:Z
{ X+]G-
this.sURL = sURL; QUQ'3
this.nStartPos = nStart; NSA-}2$
this.nEndPos = nEnd; Tc3yS(aq
nThreadID = id; liz~7RY4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WvZ8/T'x
} 0NX,QD
4tmAzD
l0i^uMS
public void run() "i W"NFO
{ g5r(>,vY
while(nStartPos < nEndPos && !bStop) ! #2{hQRu
{ xWQ`tWA:J
.y:U&Rw4
mBON$sF|
try{ b<gr@WF
URL url = new URL(sURL); >!)DM]Ri
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jma1N;d
httpConnection.setRequestProperty("User-Agent","NetFox"); P\)iZiGc
String sProperty = "bytes="+nStartPos+"-"; l_%6
httpConnection.setRequestProperty("RANGE",sProperty); g_COp"!~9
Utility.log(sProperty); <dhM\^[
c6]D-YNFG
hpL;bM'
InputStream input = httpConnection.getInputStream(); ZLAy- 9^Y
//logResponseHead(httpConnection); R@k&SlL'`
wZZt
Rr|VD@%
byte[] b = new byte[1024]; i@M[>~
int nRead; Y,zxbXZv'5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q{;:SgZ
{ Nf1-!u7
nStartPos += fileAccessI.write(b,0,nRead); l0A&9g*l2
//if(nThreadID == 1) QGmn#]w\\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SS.dY""89
} UFb)AnK
/FEVmH?
K:30_l<
Utility.log("Thread " + nThreadID + " is over!"); !f&g-V
bDownOver = true; @/-\k*T
//nPos = fileAccessI.write (b,0,nRead); "C0Q(dr/n
} b(O3@Q6[
catch(Exception e){e.printStackTrace ();} y:qUn!3
} 7o5BXF
} V[vl!XM
s#=7IH30
m5Di=8
//打印回应的头信息 N7R!C)!IL
public void logResponseHead(HttpURLConnection con) F6flIG&h
{ i5,kd~%O
for(int i=1;;i++) x>`%DwoRI
{ t" Z6[XG
String header=con.getHeaderFieldKey(i); :${HQd+
if(header!=null) zu|\fP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2WxQ(:d=
Utility.log(header+" : "+con.getHeaderField(header)); ) M BQuiL
else w%BL
break; 63,H{
} K~ehP[^
} _X"N1,0
K1!j fp
L<{i,'M
public void splitterStop() ?]Xpi3k
{ A`o8'+`C
bStop = true; HcSXsF
} m:o<XK[>
eb"5-0
__GqQUQ
} e|WJQd4+S
.O}%
q2:6QM&
/* 'K{Z{[s{
**FileAccess.java g:Xhw$x9
*//文件访问(定位，写) +<3XJ7D
package NetFox; b-Q>({=i
import java.io.*; I(7NQ8Hx
o;<Xo&
&/]Fc{]^$f
public class FileAccessI implements Serializable{ 0eu$ W
H{?vbqQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Jk=I^%~
RandomAccessFile oSavedFile; KRMQtgahc
long nPos; ^qQZT]
y^v6AM
iq( E'`d
public FileAccessI() throws IOException dD|OSB7I7
{ v4c[(&
this("",0); po Vx8oO8
} `q*M4,
};jN\x?&q
22M1j5
public FileAccessI(String sName,long nPos) throws IOException K<ft2anY5
{ ,-d0b0
oSavedFile = new RandomAccessFile(sName,"rw"); PV\+P6aIb
this.nPos = nPos; jun_QiU:2
oSavedFile.seek(nPos); m\r@@!
} p=GBUII #
:AF =<X*5
QoIT*!
public synchronized int write(byte[] b,int nStart,int nLen) mA+&Io
{ 6NM:DI\%
int n = -1; p#?7w
try{ <vh/4
oSavedFile.write(b,nStart,nLen); ]X5 9
n = nLen; nv%rJy*w[
} 2ZMb<b4H
catch(IOException e) v)l8@.
{ W;L7SF g)
e.printStackTrace (); b8"?VS5-"
} ]?+p5;{y4
`c5"d
f~y%%+{p
return n; sRx63{
} ;q:zT\A
dWUm\t'#
. Z.)t
} !GLz)#SBl
,dov<U[ia
g-HN
/* v~V5`%
**SiteInfoBean.java =;3Sx::=
*/ /!Wu D\B
package NetFox; BuWHX>H
l@H
Y/>&0wj)d
public class SiteInfoBean { TI#''XCB5
jR22t`4
9{}1r2xW
private String sSiteURL; //Site's URL z4+k7a@jn
private String sFilePath; //Saved File's Path 8:>1F,
private String sFileName; //Saved File's Name >.'*)@vQi
private int nSplitter; //Count of Splited Downloading File #PanfYR
H!nr^l'+
AW_(T\P:u
public SiteInfoBean() F\AX:
{//nSplitter的缺省值为5 C>$E%=h+_
//default value of nSplitter is 5 `m?c;,\
this("","","",5); /VzI'^
} gb> }v7
]Nl=wZ#`
]*FVz$>XM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]dk8lZ;bo
{ PBxCx3a{
sSiteURL= sURL; X4t s)>"d
sFilePath = sPath; ;A'Z4=*~
sFileName = sName; 2 :mn</z
this.nSplitter = nSpiltter; bKQ"ax>6p
rN<b?KE
H nUYqhZS
} Eu-RNrYh#
s#DaKPC
L19C<5>
public String getSSiteURL() &f^l^K5:
{ Jn3An
return sSiteURL; *l;B\=KR
} y^Kph# F"
0B&Y]*
1~ t{aLPz
public void setSSiteURL(String value) =ng\ 9y[;D
{ ks97k8B
sSiteURL = value; 80&.JP.
} TJ'[--
+$(2:S*r
K+8-9$w6
public String getSFilePath() ?(m jx
{ \&3"<6xA
return sFilePath; *U$!I?
} 2aB^WY'tC
B`o]*"xkB
0i|oYaC
public void setSFilePath(String value) rBTeb0i?
{ C2xL1`
sFilePath = value; )+"'oY$]}
} |t)}VM%
!x>%+&c>k
T?1Du"d8
public String getSFileName() VX+jadYdq
{ dT$M y`>
return sFileName; +1!qs,
} V$icWu
*^wB!{.#
{^rs#, W
public void setSFileName(String value) k`9)=&zX+
{ `S.ZS}~!F
sFileName = value; )0e2ic/
} d]i(h~?_
RUUk f({(
OXi@c;F
public int getNSplitter() ;Y mTw
{ "zY](P
return nSplitter; e9Pk"HHl
} ~-t>z
UMp/\&0
A@D2+fS
public void setNSplitter(int nCount) +|{RE.DL
{ X3:XTuV
nSplitter = nCount; )T66<UDK|
} ww{_c]My
} kR@Yl Yo
q@~L&{
~h=X8-D
/* JwRF(1_sM
**Utility.java q4$+H{xB
*/ F3lw@b3])
package NetFox; xc:!cA{V
<uk1?Qg
P;8>5;U4-
public class Utility { Enq|Y$qm
T<joRR
0T5=W U
public Utility() =!UR=Hq
{ /.eeOk
?Xo*1Z =
70Yjv1i
} $1zvgep
4E[!,zvl
//线程睡眠 LrV{j?2@
public static void sleep(int nSecond) mNAY%Wn6k
{ 9 ASb>A2~
try{ q7m6&2$[
Thread.sleep(nSecond); vF/ =J
} )|<_cwz
catch(Exception e) W Qzj[
{ lhYn5d)DV
e.printStackTrace (); q*AQq=
} MfBdNdox7
} gbStAr.
A+wv-~3
//日志 o1OBwPj
public static void log(String sMsg) Gy Qm/I
{ }Y1>(U
System.err.println(sMsg); w_4]xgS:
} =AEz9d ciS
eL.7#SIr}
h2;z4
public static void log(int sMsg) R,!Q Zxmg
{ daAyx-
System.err.println(sMsg); TfZ6F8|B
} MZSxQ8
} Ti;Ijcq8
fKa\7{R
xg{HQQ|TC
/* j?|* LT$%7
**TestMethod.java -(JUd4#
*/ {,j6\Cj4
package NetFox; '69ZdP/xX
kF V7l
yWHiw<
public class TestMethod { Zx?b<"k
6ZqgY1
0gF!!m
public TestMethod() cM&'[CI
{ ///xx/weblogic60b2_win.exe Y/8K;U|
try{ nxap\Lf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }98>5%Uv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &yz&LNn'
SiteFileFetch fileFetch = new SiteFileFetch(bean); Er:?M_ev
fileFetch.start(); 2vKx]w
} >1irSUj"~
catch(Exception e){e.printStackTrace ();} A~{f/%8D
AzpV4(:an.
$ 'QdFkOr
} `Xcirfp
4*UP.r@
:PnSQjV:
public static void main(String[] args) 4R) |->"
{ <3O T>E[
new TestMethod(); "!Rw)=7O
} IdRdW{o
} &,-p',\-
点击下载更多相关资料