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)); 9\(| D#
} 1'8YkhQ2a
for(int i=0;i<nEndPos.length-1;i++) [$UI8tV
{ hhvyf^o
nEndPos = nStartPos[i+1]; JBZ@'8eqi]
} seJ^s@H5l
nEndPos[nEndPos.length-1] = nFileLength; m1AJ{cs
} I>$&-i
} aN3;`~{9
Aos+dP5h,8
owv[M6lbD
//启动子线程 jebx40TA3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^iYj[~
for(int i=0;i<nStartPos.length;i++) R4d=S4i
{ |y!A&d=xYn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DtnEi4h,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aw>#P
nStartPos,nEndPos,i); I%Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,hmL/K0"(5
fileSplitterFetch.start(); <OPArht
} 08{@rOr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cB&:z)i4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QS`]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", poFg1
nEndPos = " + nFileLength); Ek}A]zC
// fileSplitterFetch[nPos.length-1].start(); e96k{C`j0
5@W j>:w
+"VP-s0
//等待子线程结束 ovV'VcUs
//int count = 0; +ck}l2&#
//是否结束while循环 *8XEYZa
boolean breakWhile = false; |Q>IrT
/a o5FL
:BTq!>s
while(!bStop) e>7i_4(C
{ Y <qm{e
write_nPos(); "C3/T&F
Utility.sleep(500); WMP,\=6k0
breakWhile = true; <rSF*
RCLeA=/N@0
#cLBQJq
for(int i=0;i<nStartPos.length;i++) 61 ~upQaR
{ OK gqT!
if(!fileSplitterFetch.bDownOver) CVR3 A'
{ 4nz35BLr
breakWhile = false; o%*xvH*A
break; tFl"n;~T
} sUm'
} #LN`X8Wz'
if(breakWhile) j1HW._G
break; XBw)H
9Lfv^V0
e(8Ba X_
//count++; FNId;
//if(count>4) mlS$>O_aX
// siteStop(); Q)z8PQl O
} ]"1DGg \A
eKqk= (
$,fX:x
System.err.println("文件下载结束！"); cPc</[x[W
} w:l V"]1
catch(Exception e){e.printStackTrace ();} $ o#V#
} jm r"D>
vgN&K@hJ
$7A8/#
//获得文件长度 -RK- Fu<e
public long getFileSize() _8agtQ:<
{ U|j`e5)
int nFileLength = -1; ?5 [=(\/.
try{ %GIr&V4|
URL url = new URL(siteInfoBean.getSSiteURL()); mUx+Y]Ep
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _2 osV[e
httpConnection.setRequestProperty("User-Agent","NetFox"); ;mKb]
'(jG[ry&T
c-FcEW
int responseCode=httpConnection.getResponseCode(); {P#|zp4C{
if(responseCode>=400) ',5ky{
{ ^D-/`d
processErrorCode(responseCode); n>U5R_T
return -2; //-2 represent access is error U_c*6CK
} QoH6
9490o:s
6Sn.I1Wy
String sHeader; .Rf_Cl
DrK{}uM
I ?.^ho
for(int i=1;;i++) 0NX,QD
{ _``=cc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J`1rJ
//Utility.log(in.readLine()); D*|Bb?
sHeader=httpConnection.getHeaderFieldKey(i); x.R4%Z
if(sHeader!=null) K8Y=S12Ti
{ \mlqO[ S
if(sHeader.equals("Content-Length")) R]*K:~DM
{ OY@ %p}l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P\)iZiGc
break; ijx0gh`~
} (7=9++uU
} n#_$\ p>Yd
else Vj>8a)"B5a
break; 1|-Dj|
} 8 uwq-/$
} \6*I'|5d
catch(IOException e){e.printStackTrace ();} /FEVmH?
catch(Exception e){e.printStackTrace ();} aPbE;" f
3WIk
O]1(FWYy
Utility.log(nFileLength); h2;F
7o5BXF
Czu\RXJR
return nFileLength; oIj#>1~c%
} A '];`
1Nd2{(
I83<r9
//保存下载信息（文件指针位置） (mtk 4
private void write_nPos() C/6V9;U
{ PdtvU-(
try{ `~CQU
output = new DataOutputStream(new FileOutputStream(tmpFile)); r#]WI|
output.writeInt(nStartPos.length); 63,H{
for(int i=0;i<nStartPos.length;i++) !^Y(^RS@
{ =h73s0]
// output.writeLong(nPos); "d5n \@[t
output.writeLong(fileSplitterFetch.nStartPos); ,f;}|d:r
output.writeLong(fileSplitterFetch.nEndPos); T@&K-UQ
} <<BQYU)Ig
output.close(); n^Au*'
} :+pPrGj"
catch(IOException e){e.printStackTrace ();} :A$wX$H01
catch(Exception e){e.printStackTrace ();} &(\@sxAyZ
} s#Q_Gu
wG6FS
4O Zy&,
//读取保存的下载信息（文件指针位置） n1`T#%e
private void read_nPos() <d<RK@2-
{ AuM:2N2
try{ K-Y*T}?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +wjlAqMQ
int nCount = input.readInt(); iDvpXn
nStartPos = new long[nCount]; IHfSkFz`j
nEndPos = new long[nCount]; 0kz7 >v
for(int i=0;i<nStartPos.length;i++) =tP$re";o
{ G32_FQ$b
nStartPos = input.readLong(); H!^C2
nEndPos = input.readLong(); ~)!VV)
} 6 cr^<]v!
input.close(); v @_?iC"`
} >T$7{ ~
catch(IOException e){e.printStackTrace ();} <X9T-b"$h
catch(Exception e){e.printStackTrace ();} >fhSaeN
} 7j{Te)"
aSxG|OkKy
cKSfqqPm$"
private void processErrorCode(int nErrorCode) P|yGx)'^P
{ j `w;z: G
System.err.println("Error Code : " + nErrorCode); y`T--v3mI
} u_hE7#i
cG<Q`(5~
,$ho2R),Fn
//停止文件下载 _-YL!oP
public void siteStop() LJ:mJ#
{ R'jUS7]Y
bStop = true; {EZFx,@t
for(int i=0;i<nStartPos.length;i++) GC,vQ\
fileSplitterFetch.splitterStop(); B=r]_&u-u
A)~/~
X=-gAutfE=
} V7Vbl?*n
} n$}R/*
//负责部分文件的抓取 r|u6OF>
**FileSplitterFetch.java MxFt;GgE8
*/ V!jK3vc
package NetFox; 58a)&s[+
mdmZ1:PBM
IF,i^,
import java.io.*; d;*OO xQV
import java.net.*; @+QYWh'
ir( -$*J
~5XL@jI^
public class FileSplitterFetch extends Thread { Rh05W_?Js
Cw9@2E'b
Xs.$2
String sURL; //File URL Q 37V!
long nStartPos; //File Snippet Start Position @U7#, G
long nEndPos; //File Snippet End Position v '"1/% L
int nThreadID; //Thread's ID fwar8 i1
boolean bDownOver = false; //Downing is over P22y5z~
boolean bStop = false; //Stop identical XSL t;zL:
FileAccessI fileAccessI = null; //File Access interface xIq"[?m
6KZ8 .m}:
\_-kOS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3thG*^C5
{ c)n0D=
this.sURL = sURL; 7><* 9iOW
this.nStartPos = nStart; x3p;H02i\
this.nEndPos = nEnd; %Hl:nT2M
nThreadID = id; _dJVnC1 !
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z_[3IAZ
} m,"cbJ /
%i]uW\~U
y:^>(l#;
public void run() k7Be'E BKG
{ y<Z#my$`|n
while(nStartPos < nEndPos && !bStop) -h^} jP8
{ Jte:l:yjtA
WMdz+^\(
4BUK5)B
try{ 66Cj=n5
URL url = new URL(sURL); 04T*\G^:=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2Xq!'NrS
httpConnection.setRequestProperty("User-Agent","NetFox"); VUg~[
String sProperty = "bytes="+nStartPos+"-"; n<Xm%KH.
httpConnection.setRequestProperty("RANGE",sProperty); VES4x%r=
Utility.log(sProperty); yg]nS<K~4
b`={s
"8j;k5<
InputStream input = httpConnection.getInputStream(); vSHIl"h
//logResponseHead(httpConnection); zdpLAr
88+\mX;A#
*{p&Fy55
byte[] b = new byte[1024]; lDX&v$
int nRead; lLwQridFXh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <=GzK:4L
{ z6>ZV6(d2^
nStartPos += fileAccessI.write(b,0,nRead); V n!az}
//if(nThreadID == 1) 6@_@nlA<1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X7B)jH%N
} Xk9r"RmiOb
WU4vb
;hRpAN
Utility.log("Thread " + nThreadID + " is over!"); F~0%j}ve
bDownOver = true; fKK-c9F
//nPos = fileAccessI.write (b,0,nRead); Z?j='/u>@
} fylA0{
catch(Exception e){e.printStackTrace ();} )V =K#MCK
} ]bU'G$Qm&s
} {p_vR/yN
YPJx/@Z`
(R|FQdH
//打印回应的头信息 f8_UIdM7
public void logResponseHead(HttpURLConnection con) c+K=pp@
{ kG7,1teMk
for(int i=1;;i++) QRG)~
{ {O,M}0Eg
String header=con.getHeaderFieldKey(i); DP'Dg /D
if(header!=null) ?%fZvpn-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `m0Uj9)#
Utility.log(header+" : "+con.getHeaderField(header)); 9h0,L/;\
else "Ohpb!J9
break; 3 BhA.o
} v+_Y72h*a
} oX~$'/2v
W[Ew6)1T
W%Nu]9T
public void splitterStop() w\;9&;;
{ (<~R[sT|
bStop = true; v2X0Px_
} _*B~ESC0
fB"gM2'
92ww[+RQ@
} 7tO$'q*h
[?6D1b[
W%ZU& YBc
/* ^* v{t?u
**FileAccess.java $P9$ ,w4
*//文件访问(定位，写) f<:SdtG5
package NetFox; naCI55Wx
import java.io.*; &UH z
/;m!>{({)
dnc!=Z89
public class FileAccessI implements Serializable{ >w;W&[
$ttr_4=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L"<Eov6
RandomAccessFile oSavedFile; bjX$idL
long nPos; }ucg!i3C
BCB/cBE
BFu9KS+@)
public FileAccessI() throws IOException qinQ5t
{ yj9gN}+
this("",0); {!bJ.O l
} ,qqV11P]
<:t\P.
pg`;)@
public FileAccessI(String sName,long nPos) throws IOException 6_><W"r:]
{ q)i(wEdUZ
oSavedFile = new RandomAccessFile(sName,"rw"); I<-"J^2
this.nPos = nPos; u;1NhD<n
oSavedFile.seek(nPos); I+Cmj]M s0
} Ci:QIsu*
na; ^/_U@
Ot<!YM
public synchronized int write(byte[] b,int nStart,int nLen) 2xj`cFT
{ &<b7T$c
int n = -1; d0,F'?.0|
try{ \~1+T
oSavedFile.write(b,nStart,nLen); WF0>R^SpZ
n = nLen; }TLC b/+
} Ik)Q0_<a
catch(IOException e) <p .[E]a2_
{ 'FXZ`+r|
e.printStackTrace (); Tr!X2#)A!
} O,6!`\ND
Im#$iPIvT
5E|2S_)G
return n; |th )Q
} ri`|qy6! |
=?aB@&
Inoou'jX
} ajr8tp'
g/gLG:C
~5529
/* 8A_(]Q
**SiteInfoBean.java Ca|;8ggf
*/ 9$i`B>C~
package NetFox; {}e IpK,+
Lo4t:H&
u6RHn;b
public class SiteInfoBean { u>#'Y+7
H0 t1& :
;wZ.p"T9^
private String sSiteURL; //Site's URL (H^o8J
private String sFilePath; //Saved File's Path /+YWp>6LU
private String sFileName; //Saved File's Name r>o6}Mx$
private int nSplitter; //Count of Splited Downloading File 4Rq"xYGXh
Nx'j+>bz>y
`!N?#N:b)
public SiteInfoBean() _L>n!"E/
{//nSplitter的缺省值为5 Yw0@O1Cel
//default value of nSplitter is 5 Gx($q;8
this("","","",5); *1Q?~
} DK;-2K
P])O\<)J
l"CONzm!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @}:(t{>;e7
{ /FY_LM
sSiteURL= sURL; %3wK.tR
sFilePath = sPath; tTal<4
sFileName = sName; aL}_j#m{
this.nSplitter = nSpiltter; mMH0 o
3(kZfH~
C4,W[L]4"
} A\>qoR!Y
gO%3~f!vY#
%VCHM GP=
public String getSSiteURL() ?fGY,<c
{ lKcnM3n
return sSiteURL; L 'y+^L|X
} cqDnZ`|6
E),T,
,O(uuq
public void setSSiteURL(String value) $1YnQgpT
{ W;7cF8fu4
sSiteURL = value; &>SE9w/?o
} L-yC'C
oVdmgmT.Y
~p&sd)
public String getSFilePath() <#sK~G
{ $|KbjpQ
return sFilePath; v2NzPzzyb
} bA:abO
X(~NpLR
@xo9'M<l
public void setSFilePath(String value) :7gIm|2"]
{ y7JJ[:~~
sFilePath = value; r?{tBju^
} B4%W,F:@
cOSUe_S0w[
UWz<~Vy
public String getSFileName() ] '..G-
{ `J;_!~:
return sFileName; 0=NB[eG
} +NQw^!0qy
C.eZcNJG
BO^e.iB/
public void setSFileName(String value) wml`3$"cf
{ \O[Cae:^?
sFileName = value; r!+)U#8
} rc"yEI-``"
AyddkjX
d:3G4g
public int getNSplitter() Hly$ Wm
{ &@yW<<
return nSplitter; krgsmDi7
} %%*t{0!H+
1Ypru<.)W
6u7>S?
public void setNSplitter(int nCount) YQ&Xd/z-
{ $%LjIeVA5
nSplitter = nCount; bx1'
} dLLF#N
} f5AK@]4G
) b?HK SqI
oE}1D?3Sp
/* Pl U!-7
**Utility.java QHOem=B
*/ fn)c&|aCt
package NetFox; 7tJPjp4l
uGOvZO^v
-[Q%Vv!8
public class Utility { +`zM^'^$
fDf:Jec`[
.7" f~%&oP
public Utility() D{~I
{ 42mdak}\
L9(fa+$+#
|oa9 g2
} x,pzX(
s#>Bwn&b)
//线程睡眠 |d&a&6U:
public static void sleep(int nSecond) >O?5mfMK
{ &jr'vS[b
try{ UT%^!@u
Thread.sleep(nSecond); d H]'&&M
} mJp)nF8r~
catch(Exception e) ^<Q+=\h
{ ;vnG
e.printStackTrace (); > -OQk"o
} 4fgA3%
} 1jO}{U
%Sf%XNtu
//日志 w|7<y8#qC
public static void log(String sMsg) *%bQp
{ Q0s!]Dk
System.err.println(sMsg); C;QIp6"1
} `C9/=
fo@2@
bd_&=VLTC
public static void log(int sMsg) \L Gj]mb1
{ XDRw![H,~
System.err.println(sMsg); 6SJ
} )5Mf,
} UsP1bh4
T*e>_\Tx
{N!Xp:(<7_
/* lky{<jZ%
**TestMethod.java {]ie|>'=C
*/ _\uyS',
package NetFox; =wE1j
OiAP%7i9
^UOVXRn
public class TestMethod { aAJ'0xnj
HE6kt6
rXgU*3RG
public TestMethod() csABfxib
{ ///xx/weblogic60b2_win.exe i^`]TOP
try{ x=]PE}<E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F6,[!.wl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !0p_s;uu,W
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0@ccXFE
fileFetch.start(); C 0@tMB7
} ] /w:5o#
catch(Exception e){e.printStackTrace ();} yCC.j%@
]A.:8;
E3%:7MB
} q3Tp/M.
! 3&_#VO
TX/Ng+v S
public static void main(String[] args) 0{0BL@H
{ =\uQGH
new TestMethod(); E6 glR
} m 3k}iIU7
} hqr V {c
点击下载更多相关资料