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)); VK*Dm:G0
} waI?X2
for(int i=0;i<nEndPos.length-1;i++) 86Hg?!<i.
{ .a2b&}/.d
nEndPos = nStartPos[i+1]; F]e`-;
} 2 j.6
nEndPos[nEndPos.length-1] = nFileLength; %jk7JDvl
} 7irpD7P>
} Lh%z2 5t
v+Eub;m
@~k4,dJ
//启动子线程 ,1/O2aQ%\0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Zc9@G-
for(int i=0;i<nStartPos.length;i++) oC ?UGY~xL
{ } I>68dS[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m}A|W[p<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TOapq9B]
nStartPos,nEndPos,i); GT.1,E,Vw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6&|hpp#[
fileSplitterFetch.start(); #1*#3p9UL
} [wU e"{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R!i\-C1 S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V=^B7a.;>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U\*]cw
nEndPos = " + nFileLength); VyX5MVh
// fileSplitterFetch[nPos.length-1].start(); 6$CwH!42F
Jq>rA
Z$?(~ln
//等待子线程结束 F+o4f3N
//int count = 0; %,T=|5
//是否结束while循环 M[ {O%!
boolean breakWhile = false; WC0z'N({W
Kb X&E0
-t]3 gCLb
while(!bStop) m`i_O0T
{ 88Nx/:#Y*
write_nPos(); @)#EZQix
Utility.sleep(500); YRg"{[+#]k
breakWhile = true; <OY (y#x
yFoPCA86y
$%BI8_
for(int i=0;i<nStartPos.length;i++) <W] RyEg`
{ Ri>4:V3K
if(!fileSplitterFetch.bDownOver) nTsKJX%\
{ Pi+pQFz5
breakWhile = false; "C0?s7Y
break; wZ4w`|'
} R [ZY;g:p
} rn^cajO^
if(breakWhile) )]}G8A
break; 9?X8H1
FKZ'6KM&A
yPrF2@#XZ/
//count++; 6am g*=]
//if(count>4) _'8P8T&
// siteStop(); 5P Zzaz<
} E5aRTDLq
K;z$~;F
(E;+E\E
System.err.println("文件下载结束！"); Ez8k.]qu
} *+OS;R1<
catch(Exception e){e.printStackTrace ();} c@3mfc{
} =yF]#>Ah
:V3z`}Rl
{Qi J-[q
//获得文件长度 :)Pj()Os|
public long getFileSize() N0DzFXp
{ H )51J:4
int nFileLength = -1; Y5CDdn
try{ XGuxd
URL url = new URL(siteInfoBean.getSSiteURL()); l-Be5?|{_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GO?hB4 9T
httpConnection.setRequestProperty("User-Agent","NetFox"); _aeIK
.k:heN2-x
l+#J oc<8
int responseCode=httpConnection.getResponseCode(); 0iYo&q'n
if(responseCode>=400) _01wRsm%2
{ ;6eBfMhL
processErrorCode(responseCode); jme`Tyd
return -2; //-2 represent access is error 0~~yYo&
} T;G<62`.h
wz'=
xa.tH)R
String sHeader; Ul_5"3ze
#M%K82"
0G31Kou
for(int i=1;;i++) &szYa-K*
{ V/3@iOwD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7u{V1_n1
//Utility.log(in.readLine()); ^Q6?T(%$
sHeader=httpConnection.getHeaderFieldKey(i); WBD?|Ss
if(sHeader!=null) He,,bq
{ e)= "Fq!
if(sHeader.equals("Content-Length")) ZNVrja*
{ Sn S$5o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZIKSHC9
break; %x.du9
} ]1FLG*sB
} 0 N"N$f
else 'W,*mfB
break; j7U&a}(
} 1fvN[
} PB *v45
catch(IOException e){e.printStackTrace ();} e|?eY)_
catch(Exception e){e.printStackTrace ();} 2eHVl.C5
qu1+.z=|
Uks%Mo9on
Utility.log(nFileLength); h%U}Y5Ps~
3.@LAF
5 w(nttYH
return nFileLength; HKr}"`I.
} 43x2BW&&
RC}m]!Uz
w3ATsIw
//保存下载信息（文件指针位置） _p>F43%p
private void write_nPos() O wuc9
{ &r.M~k >
try{ ; PncJe5x
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9dw* ++
output.writeInt(nStartPos.length); KF6C=,Yc%
for(int i=0;i<nStartPos.length;i++) p^|6 /b
{ wZZ~!"O&
// output.writeLong(nPos); N8pV[\f
output.writeLong(fileSplitterFetch.nStartPos); ,f{w@Er
output.writeLong(fileSplitterFetch.nEndPos); HMC-^4\%[
} =n5n
output.close(); t7l{^d_L
} 5F+G8
catch(IOException e){e.printStackTrace ();} T60pw
catch(Exception e){e.printStackTrace ();} jz`3xFy *]
} y=c={Qz@vn
gyMHC{l/B
S2DG=hi`GK
//读取保存的下载信息（文件指针位置） 67hfve
private void read_nPos() gROK4'j6y
{ ;p2b^q'
try{ WQ 2{`'z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %YK xdp
int nCount = input.readInt(); )=sbrCl,C/
nStartPos = new long[nCount]; =6qTz3t
nEndPos = new long[nCount]; xL1Li]fM!'
for(int i=0;i<nStartPos.length;i++) S.4+tf7+
{ iMt3h8
nStartPos = input.readLong(); rrr_{d/
nEndPos = input.readLong(); {g#4E0.A!
} H0#=oJr$)W
input.close(); 4uzMO<
} {aNpk,n
catch(IOException e){e.printStackTrace ();} R|}N"J_
catch(Exception e){e.printStackTrace ();} g0bYO!gCr
} gs;^SRE I
0Dna+V/jI
J,:&U wkv
private void processErrorCode(int nErrorCode) y] c1x=x
{ hVmnXT 3Z
System.err.println("Error Code : " + nErrorCode); t"Ci1"U
} En1LGi4#
u -P !2vT
RYA@{.O
//停止文件下载 !b7"K|
public void siteStop() }dop]{RG
{ Y*$>d/E
bStop = true; I-Z|FKh_C
for(int i=0;i<nStartPos.length;i++) R2n 2mQ<
fileSplitterFetch.splitterStop(); g\fj6
\7i_2|w
/ZD6pF
} =$Mf:F@
} }mXYS|{
//负责部分文件的抓取 QOo'Iv+EL
**FileSplitterFetch.java 'St6a*
*/ )PTvw>
package NetFox; ZaU8eg7
^t5My[R
>9rZVNMU
import java.io.*; ?9a%g\`?:
import java.net.*; F^'$%XKV
^L5-2;s<U'
3q}j"x?
public class FileSplitterFetch extends Thread { fCx(
\OA{&G.
VO8rd>b4
String sURL; //File URL jOVF+9M
long nStartPos; //File Snippet Start Position EC;>-s
long nEndPos; //File Snippet End Position Cp(2]Eb
int nThreadID; //Thread's ID Z.Yq)\it
boolean bDownOver = false; //Downing is over ]vlBYAW'
boolean bStop = false; //Stop identical ey=KAt
FileAccessI fileAccessI = null; //File Access interface X0u,QSt'O
q50F!yHC-
2^=.j2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3}<U'%sd
{ W\k8f+Ke
this.sURL = sURL; LXK!4(xaW
this.nStartPos = nStart; 8s$6R|ti
this.nEndPos = nEnd; |g)C `k
nThreadID = id; /T)E&=Ds
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /7 Tm2Vj8
} PQkw)D<n]_
az6&
Zt!A!Afu
public void run() Os@b8V 8,A
{ Fs(PVN
while(nStartPos < nEndPos && !bStop) nf/?7~3?[
{ b/'c h
ZrTB%
X+aQ 7^"s
try{ = 'NV3by
URL url = new URL(sURL); hr}f5Z)^v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^;RK-)
httpConnection.setRequestProperty("User-Agent","NetFox"); 80*hi)ux[
String sProperty = "bytes="+nStartPos+"-"; b&+zAt.
httpConnection.setRequestProperty("RANGE",sProperty); \~l_w ,Poo
Utility.log(sProperty); w!7ApEH1
@|SeabN^-
(c(F1=K
InputStream input = httpConnection.getInputStream(); ZpVkgX4
//logResponseHead(httpConnection); rk W7;!
5,1<A@H
0cq@lT6
byte[] b = new byte[1024]; .how@>:P+
int nRead; 93HVx#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (QiA5!wg
{ +gX,r$bX
nStartPos += fileAccessI.write(b,0,nRead); L'e^D|
//if(nThreadID == 1) &/? Ct!_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +:.Jl:fx4
} =EP`,zqn$9
{h@\C|nF
c4Zpt%:}h
Utility.log("Thread " + nThreadID + " is over!"); K:a8}w>Up
bDownOver = true; sQa;l]O:NC
//nPos = fileAccessI.write (b,0,nRead); [34N/;5
} JcR|{9ghT
catch(Exception e){e.printStackTrace ();} xmv%O&0^}
} LpU}.
} HU $"o6ap
;o!p9MEpz;
T;/GHC`{Y
//打印回应的头信息 |#@7$#j
public void logResponseHead(HttpURLConnection con) U=.PL\
{ G;l7,1;MU:
for(int i=1;;i++) v_!6S|
{ z%YNZ^d
String header=con.getHeaderFieldKey(i); B$_4ul\)
if(header!=null) ,x8;| o5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I9S;t_Z<
Utility.log(header+" : "+con.getHeaderField(header)); OOqT0wN
else J:m/s9r
break; JXK\mah
} X&pYLm72;
} N `|A
'Rn-SD~gIr
EL?(D
public void splitterStop() 'QCIKCn<
{ :5NMgR.d
bStop = true; /I`TN5~
} 6h;(b2p{
8)X9abC
c* {6T}VZr
} r(>S
KNx/1lf
m^D'p
/* DXLXGvcM
**FileAccess.java :<qe2Z5k
*//文件访问(定位，写) *,\"}x*
package NetFox; @V%\Gspv
import java.io.*; qT$k%(
c@t?R$c
_Je4&KU
public class FileAccessI implements Serializable{ }%_|k^t
Zhq_ pus"a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $D^\[^S
RandomAccessFile oSavedFile; IOl_J>D]F
long nPos; TEC^|U`G
0\dmp'j]
.EKlw##
public FileAccessI() throws IOException M~:_^B
{ KZppQ0
this("",0); ?"x4u#x
} C}8#yAS9M
b(*\4n
J2=4%#R!
public FileAccessI(String sName,long nPos) throws IOException E\[BE<y
{ 3oCI1>k
oSavedFile = new RandomAccessFile(sName,"rw"); o1.~g'!^
this.nPos = nPos; 4D?h}U /
oSavedFile.seek(nPos); !mNst$-H4
} 24jf`1XFW
W0gS>L_
I=0c\ U}
public synchronized int write(byte[] b,int nStart,int nLen) \OwF!~&
{ 9M96$i`P
int n = -1; @{y'_fw
try{ &6x(%o|
oSavedFile.write(b,nStart,nLen); '}Fe&%
n = nLen; yfG;OnkZ
} 46:<[0Psl/
catch(IOException e) uH[WlZ4
{ aCG rS{
e.printStackTrace (); +4?Lwp'q
} {iD/0q
<]rayUyaf
l/N<'T_G
return n; NL9.J@"b
} ?v2_7x&
/q9I^ztV
A,~3oQV
} B7%,D}
FuHBzBoM=
\*$^}8
/* >]h{[kU %4
**SiteInfoBean.java 51k}LH
*/ d0aXA+S%
package NetFox; Qte5E}V`
=g#PP@X]D!
hG1$YE
public class SiteInfoBean { bY~K)j v3&
?qjdmB|w
OgF[=
private String sSiteURL; //Site's URL CD`a-]6qA
private String sFilePath; //Saved File's Path HMq}){=S
private String sFileName; //Saved File's Name [DaAvN^0A
private int nSplitter; //Count of Splited Downloading File Q0J1"*P0
kF|$oBQ
m%|\AZBA#
public SiteInfoBean() z9o]);dZ
{//nSplitter的缺省值为5 >dAl*T
//default value of nSplitter is 5 IK -vcG
this("","","",5); {<-s&%/r
} :\;9y3
\Id8X`,eD
b<a3Ue%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mA(kq
{ 8SjCU+V
sSiteURL= sURL; UFB|IeX?q
sFilePath = sPath; YgEd%Z%4
sFileName = sName; /~"-q
this.nSplitter = nSpiltter; .eJKIck
Vl5r~+$|
Igo`\JY
} %xgP*%Sv2
.O-)m'5
5Q10Ohh
public String getSSiteURL() ZX_QnSNZ?
{ Q7+WV`&
return sSiteURL; KMhrw s{&B
} s\*p|vc
$xu2ZBK
Zo=,!@q(
public void setSSiteURL(String value) Ab$E@H#
{ UynGG@P@
sSiteURL = value; A;Uc&G
} QYA4C1h'
#(]D]f[@
?1\5X<|,
public String getSFilePath() k5RzW4zq;
{ SzLlJUVX
return sFilePath; HYl+xH'.j
} %pZT3dcK
"@x(2(Y&
i;HXz`vT7
public void setSFilePath(String value) SqAz((
{ (u?s@/e:`/
sFilePath = value; 5H._Q
} 6C$+D
I gJu/{:y^
o#FctM'Z
public String getSFileName() |]kiH^Ap
{ W8<QgpV*
return sFileName; ,.Gp_BI
} ir^d7CV,
h#zm+([B*
i}T*| P
public void setSFileName(String value) 5zS%F: 3
{ M.g2y&8
sFileName = value; DS8HSSD
} 2?,lr2
dwn|1%D
8i6iynR
public int getNSplitter() c<1$zQY!
{ t_/qd9Jv
return nSplitter; o9sQ!gptw
} GVT 6cR
!MSa -
i%yKyfD
public void setNSplitter(int nCount) n[/D>Pi
{ Yte*$cJ=
nSplitter = nCount; ( %sfwv
} thPAD+u.3
} %Vo'\|
$Y/z+ea
2K~v`c*4
/* XzAXcxC6G
**Utility.java pll5m7[
*/ Z{3=.z{&^=
package NetFox; y95 #t
eHx {[J?
o]0E
public class Utility { .Z7tE?
!5 S#
DvWBvs,
public Utility() _~Lu%
{ |TJ gH<I
[?z;'O}y
['(qeS@5O
} 6X ]I`e
eI|FrBq%
//线程睡眠 z{.&sr>+v
public static void sleep(int nSecond) D*L@I@ [
{ nR%w5oe
try{ ?r;F'%N=
Thread.sleep(nSecond); K*~xy bA
} c'$y_]
catch(Exception e) 8?~>FLWTXZ
{ SP0ueAa}
e.printStackTrace (); ^C,rN;mX'
} FUI/ A>
} Tu:lIy~A
ruhC:rg:/
//日志 Fkv284,LM
public static void log(String sMsg) W&A^.% 2l
{ +fvVora
System.err.println(sMsg); S?DMeZ{:
} 89[/UxM)
i{g~u<DH)Q
oKRI2ni$j9
public static void log(int sMsg) k8Dk;N
{ QKk7"2t|
System.err.println(sMsg); ,9OER!$y
} N#J8 4i;ry
} l2#~
6hcs)X7m
#E4oq9{0*W
/* ^g'uR@uU
**TestMethod.java N]BH67<
*/ w&U28"i>
package NetFox; :hHKm|1FE
UeUOGf ,
Na\&}GSf^
public class TestMethod { jcePSps]
Jcvp<
$hM9{
public TestMethod() Kd}%%L
{ ///xx/weblogic60b2_win.exe .Sm 8t$
try{ z#5qI',L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {s@&3i?ZiC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LWo)x
SiteFileFetch fileFetch = new SiteFileFetch(bean); JpQV7}$
fileFetch.start(); lfoPFJ Z
} 8yr-X!eF
catch(Exception e){e.printStackTrace ();} tjZS:@3 Z
r*7J#M /
NR^Z#BU
} &sq q+&ao
c:DV8'fT
<95*z @
public static void main(String[] args) +C$wkx]
{ ZU:c[`
new TestMethod(); V" 5rIk
} 4YMUkwh
} R<T5lkJ\/
点击下载更多相关资料