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)); I8YCXh
} .nEiYS|T
for(int i=0;i<nEndPos.length-1;i++) k)W&ZY
{ Q8.LlE999
nEndPos = nStartPos[i+1]; kdhwnO
} 4Tb"+Y}
nEndPos[nEndPos.length-1] = nFileLength; wti
} >5D;uTy u
} ViG>gMGv
\p]B8hLW
#wZH.i#
//启动子线程 n9R0f9:*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8xkLfN|N=
for(int i=0;i<nStartPos.length;i++) U*go}dt"5
{ U"~W3vwJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KleiX7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5Yww,s
nStartPos,nEndPos,i); oY7jj=z#T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .1_kRy2*.
fileSplitterFetch.start(); \^jRMIM==
} wyXQP+9G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @rF|WT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :H+8E5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MIh\z7gW
nEndPos = " + nFileLength); 1xSG(!
// fileSplitterFetch[nPos.length-1].start(); #&%>kfeJ)<
q1m{G1W n
^`Hb7A(
//等待子线程结束 kv;P2:"|
//int count = 0; 77ztDQDtM
//是否结束while循环 Ds#BfP7a
boolean breakWhile = false; ,J:Ro N_:
q>5j (,6F
cS Qb3}a\
while(!bStop) Fh|{ib
{ yhs:.h
write_nPos(); OB*V4Yv
Utility.sleep(500); {<?8Y
breakWhile = true; .N`*jT
T)',}=
Ba**S8{/`
for(int i=0;i<nStartPos.length;i++) :\y' ?d- Q
{ IIAmx[ b
if(!fileSplitterFetch.bDownOver) L|6I
{ T;V!>W37
breakWhile = false; DgY !)cS
break; |"+Ufw^
} `3@?)xa
} 1I)oT-~
if(breakWhile) C2\zbC[qm
break; A~ _2"
*N"CV={No
n=|% H'U
//count++; C7DwA/$D
//if(count>4) <XN=v!2;
// siteStop(); NCl@C$W9q
} d`~~Ww1
-:OJX#j
FZLx.3k4
System.err.println("文件下载结束！"); c] t@3m
} h_SkX@"/-
catch(Exception e){e.printStackTrace ();} II!~"-WH
} =G"ney2
K9y~ e
TPak,h(1
//获得文件长度 ww #kc!'
public long getFileSize() C\B4Uu6q
{ j-.Y!$a%6
int nFileLength = -1; |qz%6w=
try{ f8`dJ5i
URL url = new URL(siteInfoBean.getSSiteURL()); n9n)eI)R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p@[ fZj
httpConnection.setRequestProperty("User-Agent","NetFox"); <fV][W
yc`*zLWh
q6<P\CSHy<
int responseCode=httpConnection.getResponseCode(); P,F eF'J^
if(responseCode>=400) -4P `:bF
{ o{^`Y
processErrorCode(responseCode); KHgn
return -2; //-2 represent access is error d ez4g
} ]}p<P):hO
ge<D}6GQ
._Ww
String sHeader; b4WH37,lA
?_cOU@n
lk[Y6yE
for(int i=1;;i++) ]vP}K
{ e =r b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1<5Ug8q
//Utility.log(in.readLine()); >P&1or)e%
sHeader=httpConnection.getHeaderFieldKey(i); 1@JusS0^K
if(sHeader!=null) $EX(-!c
{ xV 2C4K
if(sHeader.equals("Content-Length")) 7D4tuXUq2
{ NzTF2ve(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4d-(:
break; egURRC!
} v"Ax'()
} C/'w
else 44|tCB`
break; >]~|Nf/i
} }a.j~>rq
} HD/!J9&
catch(IOException e){e.printStackTrace ();} %OHZOs
catch(Exception e){e.printStackTrace ();} %.?V\l
E)ZL+(
:O$bsw:3w<
Utility.log(nFileLength); OZnKJ<
^YropzHZ4E
&i.sSqSI5
return nFileLength; 7GWOJ^)
} 7CvBE;i
Qh(X7B
FROC/'
//保存下载信息（文件指针位置） >%0$AW|Exu
private void write_nPos() _B&Lyg!J
{ !!H"B('m
try{ l{>j8Ln
output = new DataOutputStream(new FileOutputStream(tmpFile)); r[H8;&EL
output.writeInt(nStartPos.length); @NqwJ.%g
for(int i=0;i<nStartPos.length;i++) BP0:<vK{
{ W)/^*, Q7
// output.writeLong(nPos); "Y=`w,~~
output.writeLong(fileSplitterFetch.nStartPos); T'@+MA) ~
output.writeLong(fileSplitterFetch.nEndPos); >m..
} oPM*VTMA
output.close(); #j=yQrJ
} G{E`5KIvm
catch(IOException e){e.printStackTrace ();} Zd-6_,r
catch(Exception e){e.printStackTrace ();} 2wHbhW[
} y& 1@d+Lf
?1a9k@[t
ne/JC(
//读取保存的下载信息（文件指针位置） F_jHi0A
private void read_nPos() \m GY'0
{ $2L6:&.P,
try{ 6CIzT.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -p.\fvip
int nCount = input.readInt(); ZcQu9XDIt
nStartPos = new long[nCount]; va'F '|
nEndPos = new long[nCount]; E3]WRF;l
for(int i=0;i<nStartPos.length;i++) So'.QWzX
{ *{!Y_FrL
nStartPos = input.readLong(); fzQR0
nEndPos = input.readLong(); $R1I(sJ
} ,0q1Id
input.close(); ]MosiMJF
} h0@a"DqK
catch(IOException e){e.printStackTrace ();} f$ xp74hw3
catch(Exception e){e.printStackTrace ();} W%-XN
} U/QgO
|#kY_d)10
rUj\F9*5#
private void processErrorCode(int nErrorCode) ]b!n ;{5
{ -` U|5
System.err.println("Error Code : " + nErrorCode); EZ]4cd/i
} EN2SI+
vjlN@ "
pUb1#=
//停止文件下载 ^hmV?a:Y
public void siteStop() U`mX f#D
{ bIAE?D
bStop = true; P<<+;']
for(int i=0;i<nStartPos.length;i++) ,0.kg
fileSplitterFetch.splitterStop(); yJq<&g
y]m: {
AcPLJ!y
} Aj4 a-vd.
} kz7FQE
//负责部分文件的抓取 VTM* 1uXS>
**FileSplitterFetch.java :aej.>I0
*/ -}|L<~
package NetFox; KBmOi
% D
*;Mi/^pzK
import java.io.*; |'nQvn:{
import java.net.*; VAz4@r7hkq
LV^^Bd8Ct
v$|~ g'6
public class FileSplitterFetch extends Thread { 3SP";3+
:*M?RL@j
m-vn5OX
String sURL; //File URL K)7T]z`
long nStartPos; //File Snippet Start Position l<f9$l^U
long nEndPos; //File Snippet End Position 8(L$a1#5W
int nThreadID; //Thread's ID 25$_tZPAI
boolean bDownOver = false; //Downing is over X8$Mzeq
boolean bStop = false; //Stop identical >u&D@7~c
FileAccessI fileAccessI = null; //File Access interface .d]/:T -0
h|CZ~
oAQQ OtpZN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hul,Yd) Z
{ 6dRhK+|
this.sURL = sURL; f^uiZb
this.nStartPos = nStart; 4]h/t&ppq
this.nEndPos = nEnd; WiS3W;
nThreadID = id; rPaJ<>Kz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &q-&%~E@
} AG@gOm
c>_ti+
)S g6B;CJ
public void run() D_DwP$wSo
{ k&ci5MpN
while(nStartPos < nEndPos && !bStop) &zdS9e-fF
{ ""0Y^M2I
Rql/@j`JX
ga5Q
try{ 9\_AB.Z:
URL url = new URL(sURL); /?'~`4!(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K ze?@*
httpConnection.setRequestProperty("User-Agent","NetFox"); fp' '+R[
String sProperty = "bytes="+nStartPos+"-"; }=[p>3Dd
httpConnection.setRequestProperty("RANGE",sProperty); _;j1g%
Utility.log(sProperty); 8tx*z"2S
*[Z`0AgP
>GGM76vB=,
InputStream input = httpConnection.getInputStream(); !p&<.H_
//logResponseHead(httpConnection); `Nx@MPo
Z7a@$n3h
WNGX`V,d
byte[] b = new byte[1024]; WHdMP
int nRead; !9;m~T7.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) # )y`Zz{h
{ ,8@<sFB'
nStartPos += fileAccessI.write(b,0,nRead); D&%8JL
//if(nThreadID == 1) o08WC'bX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |g&V? lI
} Lv%3 jj
{N4 'g_
4z0gyCAC A
Utility.log("Thread " + nThreadID + " is over!"); .l1x~(
bDownOver = true; ?+t;\
//nPos = fileAccessI.write (b,0,nRead); ys9:";X;}
} |]?f6^|4
catch(Exception e){e.printStackTrace ();} F1#{(uW
} q`*.F#/4c
} |[?Otv
ieZ$@3#&z
u#76w74
//打印回应的头信息 B$eM
public void logResponseHead(HttpURLConnection con) ):$KM{X
{ OcTWq
for(int i=1;;i++) YEu+kBlcQ
{ os/h~,=
String header=con.getHeaderFieldKey(i); fsL9d}
if(header!=null) @+b$43^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f24W*#IX
Utility.log(header+" : "+con.getHeaderField(header)); C+NN.5No
else ``l*;}
break; ${Un#]g
} xt^1,V4Ei~
} }Va((X w
/wJ#-DZ
&=[!L0{
public void splitterStop() @z1QoZ^w
{ \zBi-GI7
bStop = true; 1&boD\ 7
} \CjJa(vV
w}3N!jNDv
X _ZO)|
} 5?0<.f,
|+ F ~zIu'
1#d2 +J*
/* W.j^L;
**FileAccess.java _k@cs^
*//文件访问(定位，写) $JY\q2
package NetFox; ]}L'jK 0
import java.io.*; wH~A> 4*(
cGV%=N^BE<
PuNL%D
public class FileAccessI implements Serializable{ v@\S$qU2
`etw[#~N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |vs5N2_
RandomAccessFile oSavedFile; DTezG':
long nPos; ~+\=X`y
o/{`\4
'[$KG
public FileAccessI() throws IOException ,JwX*L<:
{ ED` 1)1<
this("",0); 7KIekL
} P]Fb0X
rH7Cv/Y
~5P9^`KNH
public FileAccessI(String sName,long nPos) throws IOException 8jz>^.-o
{ qyRN0ZB"A^
oSavedFile = new RandomAccessFile(sName,"rw"); B?j t?
this.nPos = nPos; /|v4]t-
oSavedFile.seek(nPos); H:DR?'yW
} [%K6-\S
S^%3Vf}
BE0l2[i?
public synchronized int write(byte[] b,int nStart,int nLen) EE"8s7ZF
{ l[E^nh>
int n = -1; $mJv\;t
try{ .z#eYn%d
oSavedFile.write(b,nStart,nLen); };'@'
n = nLen; B:"D)/\
} 7NvKpinQ
catch(IOException e) V(`]hH0;T
{ _#{*I(l
e.printStackTrace (); ~R|9|k
} Tt: (l/1
2;Z 0pPR&
r?DCR\Jq
return n; 'l'3&.{Yfk
} :ts3_-cr
O\<zQ2m
)BJkHED{
} 6:8s,a3&[k
GN_L"|#)=
FAM{p=t]HT
/* Au2?f~#Fv
**SiteInfoBean.java i]MemM-
*/ 9^/Y7Wp/@
package NetFox; `KZV@t
N:lE{IvRJ
,V1"Typ#<
public class SiteInfoBean { _<AkM"
b+~_/;Y9
Z^'~iU-?
private String sSiteURL; //Site's URL T";evM66
private String sFilePath; //Saved File's Path sK#)k\w>
private String sFileName; //Saved File's Name ST{Vi';}
private int nSplitter; //Count of Splited Downloading File a_Xwi:e<
.=eEuH
dfFw6R
public SiteInfoBean() c'Z=uL<Rm
{//nSplitter的缺省值为5 WWpMuB_G
//default value of nSplitter is 5 y]Nk^ga:U6
this("","","",5); =q VT
} =2$( tXL
C_J@:HlJ
uX-^9t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =dQ[I6
{ uGZGI;9f4
sSiteURL= sURL; |3~m8v2-
sFilePath = sPath; RG'iWA,9m`
sFileName = sName; &5y
this.nSplitter = nSpiltter; Pg}QRCB@
1o&zA<+NY
nXn@|J&z~U
} 3(oMASf
AFi_P\X
J$6WUz:?
public String getSSiteURL() 1 *' /B
{ P^OmJ;""D
return sSiteURL; }-fHS;/
} BWxfY^,'&6
O7 ;=g!j
l73% y
public void setSSiteURL(String value) H~yHSm 3
{ ?pZ"7kkD
sSiteURL = value; _#V&rY&@
} e:HORc~U
1'/ [x(/]d
OB.rETg
public String getSFilePath() yBy7d!@2
{ tU?BR<q
return sFilePath; dU3A:uS^
} T^4 dHG-(
;B@#,6t/
\:+\H0Bz
public void setSFilePath(String value) :!_l@=l
{ 8gavcsVE[
sFilePath = value; 0U7Gl9~
} [~8U],?1
'd2 :a2C]
<TVJ9l
public String getSFileName() ;j9%D`u<
{ *OA(v^@tx7
return sFileName; _>vH%FY
} 81EEYf
,f^fr&6jb
v7pu
public void setSFileName(String value) (kR NqfX
{ \0~?i6o
sFileName = value; rf=l1GW
} <P#BQt f
[y8(v ~H
H{n:R *
public int getNSplitter() rQl9SUs
{ d0B`5#4
return nSplitter; bit|L7*14
} /Pextj<
E0I/]0
_]@u)$
public void setNSplitter(int nCount) $,K@xq5
{ rG?5z"
nSplitter = nCount; q;#AlquY@
} ho$}#o
} HWV A5E[`Y
ogIu\kiZ
EmaS/]X[
/* c1E{J<pZ
**Utility.java [s$x"Ex
*/ ?;oJ=.T
package NetFox; `xx.,;S
pnuo;rs
~qZ6I)?
public class Utility { $e+4Kt ,
uD(C jHM>
.nZKy't
public Utility() 0UJ6>Rj
{ yf&_l^!
2FZT
S!PG7hK2
} v@]SddP,?
>TglX t+
//线程睡眠 kcUn GiP
public static void sleep(int nSecond) k.b=EX|
{ 9ye!kYF,
try{ \FfqIc9;
Thread.sleep(nSecond); +@]k[9
} \ n2MP
catch(Exception e) :rM2G@{
{ ,Z @I"&H
e.printStackTrace (); eyh}O
} 0rL.~2)V
} Lxv;[2XsW)
JkN*hm?
//日志 r-YJ$/J
public static void log(String sMsg) 7vXP|8j
{ ll0y@@Iy
System.err.println(sMsg); C-A? mIC
} Sed8Q-m
Ej)7[
L{VnsY V
public static void log(int sMsg) 4L:O0Ggz}
{ ~S<aIk0l
System.err.println(sMsg); hiibPc?I
} z2{y<a9;?
} mKu,7nMvF
-BP10-V
Ms+ekY)
/* OIj.K@Kr
**TestMethod.java Y!45Kio
*/ Z$INmo6
package NetFox; JmDxsb^
3#'8S_
vE,^K6q0`
public class TestMethod { hBRi5&%
L754odc
;6 W[%{
public TestMethod() Csy$1;"A
{ ///xx/weblogic60b2_win.exe xTuJ~$(
try{ eYP^.U)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }F0<8L6%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pYzop4
SiteFileFetch fileFetch = new SiteFileFetch(bean); dhA~Yu
fileFetch.start(); 2]?=\_T
} ,\iXZ5"R
catch(Exception e){e.printStackTrace ();} 59{X;
'm`}XGUBS
.s>@@m-
} K"VcPDK
5?HwM[`
N@tKgx
public static void main(String[] args) ~tWh6-:|{J
{ _BA; H+M
new TestMethod(); LI@BB:)[
} #8M?y*<I
} hFm^Fy[R
点击下载更多相关资料