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)); "cX*GTNi8
} V, e
for(int i=0;i<nEndPos.length-1;i++) p:qj.ukw
{ j=w`%nh4"f
nEndPos = nStartPos[i+1]; qo0]7m7|
} QLyBP!X-
nEndPos[nEndPos.length-1] = nFileLength; PF-"^2&_
} ON$-g_s>)
} Z65]|
&M+fb4:_
_6'HBE
//启动子线程 _qhYG1t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CFx$r_!~
for(int i=0;i<nStartPos.length;i++) W_G'wU3R
{ lmr:PX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \YsYOFc|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6Vc&g
nStartPos,nEndPos,i); TWJ%? /d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?1MaA
fileSplitterFetch.start(); v]BMET[w
} 4O3-PU>N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gR) )K)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6\?<:Qto
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n>I NJ
nEndPos = " + nFileLength); xn4-^2
// fileSplitterFetch[nPos.length-1].start(); hlTM<E
_cH 7lO[
Tg.}rNA4
//等待子线程结束 626!6E;T
//int count = 0; i9k/X&V
//是否结束while循环 .TetN}w
boolean breakWhile = false; q/yL={H?
Sf*b{6lcC
Gd%E337d
while(!bStop) nc.X+dx:
{ _8"%nV
write_nPos(); qU,u(El
Utility.sleep(500); 6'qC *r
breakWhile = true; m%km@G$
>~k"C,6
YV>]c9!q
for(int i=0;i<nStartPos.length;i++) X Sw0t8
{ 2N:|BO>
if(!fileSplitterFetch.bDownOver) cp>1b8l6?
{ Q'S"$^~{
breakWhile = false; k\a&4v
break; r+%}XS%;h
} X,8]g.<
} :;]iUjiC8
if(breakWhile) lZ9rB^!
break; P>3 ;M'KsO
vmZyvJSE
0? QTi(
//count++; /^<Uy3F[p
//if(count>4) [q{[Avqf
// siteStop(); S( r Fa
} u4a(AB>S
mxJ& IV
qE&R.I!o
System.err.println("文件下载结束！"); |[}!E/7>b
} yk|<P\
catch(Exception e){e.printStackTrace ();} fSFb)+
} <wZ2S3RNA
N3J;_=<4
|B;tv#mKD
//获得文件长度 Ma,2_oq+
public long getFileSize() ]V K%6PQ0
{ .`3O4]N[
int nFileLength = -1; e1j3X\ \
try{ u 6(O;
URL url = new URL(siteInfoBean.getSSiteURL()); (}u2) 9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]l WEdf+
httpConnection.setRequestProperty("User-Agent","NetFox"); vC9Qe ]f
$ RDwy)9
s8/y|HN^
int responseCode=httpConnection.getResponseCode(); ;NHZD
if(responseCode>=400) ;L458fYs
{ T!*lTzNHm
processErrorCode(responseCode); Z4 +6'
return -2; //-2 represent access is error k_hV.CV
} $R2iSu{kO
yIL6Sb
z_^Vgb]
String sHeader; MM*B.y~TxZ
.A. VOf_
As;@T$G
for(int i=1;;i++) 5QR=$?K
{ zMf.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vO#=]J8`
//Utility.log(in.readLine()); L:ox$RU
sHeader=httpConnection.getHeaderFieldKey(i); $6evK~
if(sHeader!=null) /uM;g9 m
{ ju-tx :
if(sHeader.equals("Content-Length")) )oRF/Xx`g
{ B8Cic\2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kIlc$:K^
break; 1@)kNg)*$
} M[^
} ueyz@{On~
else Mbua!m(0
break; /Jjub3>Q
} %)$^_4.g
} i*Wekr3Wo
catch(IOException e){e.printStackTrace ();} ur,!-t(~t
catch(Exception e){e.printStackTrace ();} {WE1^&Vk-}
V kA$T8
[!ghI%VK
Utility.log(nFileLength); wsnR$FhQ`
aeQvIob@
h2SVDKj
return nFileLength; 9Q<8DMX^
} WPmH4L>T
K\7\
[<+A?M=
//保存下载信息（文件指针位置） 5v f?E"\r
private void write_nPos() fZqqU|tq
{ !y&uK&1
try{ }Ss]/_t
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;wi}6rF%[i
output.writeInt(nStartPos.length); zq=X;}qYj
for(int i=0;i<nStartPos.length;i++) ZH:-.2*cj
{ mUmU_L u8
// output.writeLong(nPos); [\ M$a|K
output.writeLong(fileSplitterFetch.nStartPos); s[ ze8:
output.writeLong(fileSplitterFetch.nEndPos); yM*-em
} @%7IZg;P6
output.close(); H\Y5Fd9)
} ?*36&Iq}
catch(IOException e){e.printStackTrace ();} WUwH W
catch(Exception e){e.printStackTrace ();} []'gIF
} 8!~8:?6n
4&}V3"lg
H]6i1j
//读取保存的下载信息（文件指针位置） 2qw-:
private void read_nPos() ''{REFjK7
{ vr,8i7*0
try{ `OL@@`'^{S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xu4C*]A>
int nCount = input.readInt(); g>m)|o'
nStartPos = new long[nCount]; B}PT-S1l
nEndPos = new long[nCount]; "$->nC.
for(int i=0;i<nStartPos.length;i++) wxa?.
{ u3"0K['3
nStartPos = input.readLong(); S_E-H.d"
nEndPos = input.readLong(); 0Jz5i4B
} oNyVRH ZH
input.close(); 7,MDFO{n
} [1-1^JY
catch(IOException e){e.printStackTrace ();} w1aev
catch(Exception e){e.printStackTrace ();} }e7os0;s
} o$*aAgS+
gx-ib/_f1
,g.*Mx`-
private void processErrorCode(int nErrorCode) 'pCZx9*c
{ |[/<[@\''
System.err.println("Error Code : " + nErrorCode); {:D8@jb[
} {XHAQ9'
PTU_<\
V`/E$a1&
//停止文件下载 qc(R /[
public void siteStop() C 2f=9n/
{ p#5U[@TK
bStop = true; O_9M /[<
for(int i=0;i<nStartPos.length;i++) 9g7d:zG
fileSplitterFetch.splitterStop(); BHVC&F*>
y&ZyThqg
B3+9G,or
} $+ z3
} Q]JWWKt6rV
//负责部分文件的抓取 hA6
**FileSplitterFetch.java (E{>L).~
*/ `!`g&:Y
package NetFox; R`[jkJrc
''bh{ .x
DFgQ1:6[
import java.io.*; ?Uq;>
import java.net.*; z\d{A7
8#m,TOp
\dm5Em/
public class FileSplitterFetch extends Thread { prHM}n{0
s+tPHftp
.3X5~OH
String sURL; //File URL CIxa" MW
long nStartPos; //File Snippet Start Position e=>:(^CS
long nEndPos; //File Snippet End Position 1@dB*Jt
int nThreadID; //Thread's ID ^(j}'p,
boolean bDownOver = false; //Downing is over )8cb @N
boolean bStop = false; //Stop identical K nl`[Nl
FileAccessI fileAccessI = null; //File Access interface `"(FWK=8)"
l}bAwJ?
"QKCZ8_C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException og`rsl
{ &$$o=Yg,
this.sURL = sURL; _>8rTk`/h
this.nStartPos = nStart; Ulf'gD4e
this.nEndPos = nEnd; r}**^"mFy
nThreadID = id; H*m3i;"4p\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t@&U2JaL>W
} %O69A$Q[m
l&/V4V-
NmuzAZr
public void run() L@5j? N?F
{ (-no`j
while(nStartPos < nEndPos && !bStop) DruiiA
{ 9{GEq@`7
x>cl$41!W
_xefFy
try{ o=nF.y
URL url = new URL(sURL); }T5 E^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ybkydc
httpConnection.setRequestProperty("User-Agent","NetFox"); ;p(I0X
String sProperty = "bytes="+nStartPos+"-"; g@O H,h/
httpConnection.setRequestProperty("RANGE",sProperty); `SH14A*
Utility.log(sProperty); W ZT) LYA
z/I\hC9i
&-$27
InputStream input = httpConnection.getInputStream(); 7DKTd^^M
//logResponseHead(httpConnection); V0<g$,W=
68UfuC
;/h&40&
byte[] b = new byte[1024]; xZ]QT3U+
int nRead; -U{CWn3G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !X[P)/?b0+
{ ]#\De73K
nStartPos += fileAccessI.write(b,0,nRead); O**~ Tj
//if(nThreadID == 1) uq2C|=M-x\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *N|ak =
} GGs7]mhA
j"s7P%
rJTYCe1*
Utility.log("Thread " + nThreadID + " is over!"); Y3\EX
bDownOver = true; :jf/$]p
//nPos = fileAccessI.write (b,0,nRead); .k-t5d
} b/w5K2
catch(Exception e){e.printStackTrace ();} I&6M{,rnM
} Q!!u=}GYK
} @#p6C
rEMe=>^
' Tk4P{
//打印回应的头信息 /iEQ}
public void logResponseHead(HttpURLConnection con) z1^3~U$}
{ v5 @9
for(int i=1;;i++) D<`M<:nq
{ f5Hv![x
String header=con.getHeaderFieldKey(i); sd"eu
if(header!=null) X`(fJ',
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lWn}afI
Utility.log(header+" : "+con.getHeaderField(header)); ^?2zoS#iw
else w!pj);jy{
break; '5b0 K1$"
} {r~=mQ
} ify48]
lCgzQZ
B]NcY&A
public void splitterStop() ZWni5uF-c
{ |2=@8_am
bStop = true; 5UJ ?1"J
} tLU@&NY`
$) M2
%JH/|mA&|
} &8pGq./lr=
tDavp:M1v
%gQUog
/* NJSbS<O
**FileAccess.java w?zy/+N~
*//文件访问(定位，写) Bd 0oA )i
package NetFox; &Nh zEl1
import java.io.*; P*B@it
aOw#]pB|
LEOri=?RF
public class FileAccessI implements Serializable{ x[$KZGK+GL
$f _C~O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9XYm8g'X
RandomAccessFile oSavedFile; ce#Iu#qT
long nPos; xAl8e
.zl[nx[9"D
F:d2;
public FileAccessI() throws IOException zy%0;%
{ B'Jf&v
this("",0); 4:S]n19nq
} &ds+9A
xJAQ'ANr
kI9I{ &J&
public FileAccessI(String sName,long nPos) throws IOException }!{R;,5/n
{ \<(EV,m2
oSavedFile = new RandomAccessFile(sName,"rw"); n$XEazUb0N
this.nPos = nPos; :4-,Ru1C"
oSavedFile.seek(nPos); +Adk1N8
} ^>&#F[aT
@C!&lrf3
NP\mzlI~@
public synchronized int write(byte[] b,int nStart,int nLen) 5jso)`IL
{ X.S<",a{qz
int n = -1; LGW:+c
try{ pW@W-k:u
oSavedFile.write(b,nStart,nLen); -.y1]4
n = nLen; [|YvVA
} SD:D8"8
catch(IOException e) b9#(I~}
{ kW2DKr-[
e.printStackTrace (); zwU[!i)
} Tg"? TZO~
?}v/)hjp=?
99`w'Nlk
return n; {d*OJ/4
} _Y;tD
Ihf)gfHj
B @QWr;
} Su7N?X!
LEeA ,Y
=cZ24I
/* d5>&, {o7N
**SiteInfoBean.java 1KrJS(.
*/ akt7rnt?i
package NetFox; hrq% {!Z
m7y[Y
=]-z?O6^`
public class SiteInfoBean { ye=4<b_
A-:k4] {%P
KpYezdPF)
private String sSiteURL; //Site's URL @XolFOL"f"
private String sFilePath; //Saved File's Path `_1~[t
private String sFileName; //Saved File's Name CEI"p2
private int nSplitter; //Count of Splited Downloading File * 30K}&T
O=V_7I5
RqGX(Iuv
public SiteInfoBean() aVHIU3
{//nSplitter的缺省值为5 ^~-YS-.J#,
//default value of nSplitter is 5 te2vv]W1
this("","","",5); KcpYHWCa.
} >h\u[I$7
Lo_+W1+
xx>hJ!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C 'MR=/sd
{ 'nGUm[vh
sSiteURL= sURL; ,lA@C2c
sFilePath = sPath; OqIXFX"
sFileName = sName; eK l;T
this.nSplitter = nSpiltter; 3m!tb)
5v)bs\x6
iLZY6?_^
} Ms,MXJtH
dt:$:,"
a{r"$>0
public String getSSiteURL() r9&m^,U
{ yD7}
return sSiteURL; kMurNA=
} O7 aLW
V=*^C+6s
5Y^"&h[/
public void setSSiteURL(String value) :K]7(y7>
{ FMeBsI9pL
sSiteURL = value; Wj^e)2%
} El5} f4sl
K2yNIq_
cbyzZ#WRb
public String getSFilePath() p9?kJKN
{ ^@AyC"K
return sFilePath; -)oUb=Lk{
} [,Go*r
]/1\.<uJId
#l4T/`u'9!
public void setSFilePath(String value) |EX=Rj*
{ }q@#M8b
sFilePath = value; i,*m(C@F}
} 9;U?_
t kj
Y /_CPY
public String getSFileName() dREY m}1
{ 3r kcIVO
return sFileName; sd\p[MXX
} q/U-6A[0
$xZ ~bE9
Icrnu}pl_
public void setSFileName(String value) N7J?S~x
{ 8^ f:-5
sFileName = value; {:uv}4Z
} )e?&'wa>
lUs$I{2_
j0mN4Ny
public int getNSplitter() i)|jLrW~e
{ 6EyPZ{
return nSplitter; ZK^cG'^2|
} &}k7iaO
X>o9mW
7:u+cv
public void setNSplitter(int nCount) )/::i O&$:
{ j %gd:-tA
nSplitter = nCount; +,>%Yb=EA
} 0W*{ 1W
} U*$P"sS`
xrg?{*\
Y)X7*iTi'j
/* E@ U]k$M
**Utility.java bJ!\eI%ld
*/ JyMk @Y
package NetFox; M/Yr0"%Q<.
+`Z1L\gmA
NAvR^"I~
public class Utility { !|&|%x6@
*tF~CG$r
wL?Up>fr
public Utility() v&YeQC>
{ #%p44%W
c,2& -T}
Lkm-<
} tf~B,?
w_56y8Pd4
//线程睡眠 Kt_oo[ey{
public static void sleep(int nSecond) +r8bGS]ki
{ &*<27-x
try{ A ]A{HEX
Thread.sleep(nSecond); ^r\rpSN
} JkAM:,^(
catch(Exception e) sg $db62>
{ yv[j Pbe
e.printStackTrace (); }UW7py!TN
} luf5-XT
} g^]Iw~T6$
XX~vg>3_
//日志 ':wf%_Iw
public static void log(String sMsg) c 3QgX4vq
{ VyxYv-$Y
System.err.println(sMsg); 1XSnnkJm
} s7 "xDDV
x"12$79=
:]-oo*xP
public static void log(int sMsg) sW]^YT>?
{ -XV,r<''
System.err.println(sMsg); +'?Qph6o,7
} | ;tH?E
} /sKL|]i=
l/X_CM8y~
o{s2T)2
/* [MTd<@
**TestMethod.java !LN8=u.
*/ tUv>1) [
package NetFox; >D,Oav
xPm. TPj
=:WZV8@%
public class TestMethod { 8v"rM >[
ebk>e*
EU?qLj':
public TestMethod() {[oNUzcd
{ ///xx/weblogic60b2_win.exe ff#7}9_mh
try{ \Z]+j@9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nj[TTndJt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `>:5[Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); \HeJc:^
fileFetch.start(); h&<"jCjL
} $xbC^ k
catch(Exception e){e.printStackTrace ();} 9pp+<c
;28d7e}
*r`=hNr
} v/`D0g-uX)
(u,)v_Oo]a
x%B_v^^^
public static void main(String[] args) ?Z#N9Z~\
{ OsgPNy0
new TestMethod(); !Z!)$3bB
} *d1BpR%
} kt6x"'"1
点击下载更多相关资料