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)); 8]\h^k4f
} {fv8S;|u
for(int i=0;i<nEndPos.length-1;i++) FF~4y>R7u
{ neFno5dj
nEndPos = nStartPos[i+1]; OZm[iH
} D.R
nEndPos[nEndPos.length-1] = nFileLength; \#,#_
} "Cj#bUw
} ix@rq#
3uG5b8?
L.[uMuUa
//启动子线程 7`@?3?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0\nhg5]?
for(int i=0;i<nStartPos.length;i++) \Pmk`^T
{ )#~fS28j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %esZ}U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (1j$*?iGA
nStartPos,nEndPos,i); L"6/"L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $ _Bu,;
fileSplitterFetch.start(); / i2-h
} 4(GgaQFO?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WCTW#<izm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `Kw8rG\]:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RmV/wY
nEndPos = " + nFileLength); nY-9 1q?Y
// fileSplitterFetch[nPos.length-1].start(); Ytwv=;h-
3|r!*+.
pY>-N
//等待子线程结束 L)Ar{*xC
//int count = 0; }QW~.>`
//是否结束while循环 0a6z"K}
boolean breakWhile = false; S_VncTIO
-f|^}j?
B2qq C-hw?
while(!bStop) +u:OAsR
{ "gajBY
write_nPos(); FXEfD"
Utility.sleep(500); #n)W
breakWhile = true; DLVs>?Y
[HiTR!o*
<?7,`P:h[
for(int i=0;i<nStartPos.length;i++) ||ZufFO
{ XfK.Fj~-
if(!fileSplitterFetch.bDownOver) *Q120R
{ -U;LiO;N
breakWhile = false; &|"I0|tJ
break; '!h0![OH
} (DP9& b
} MGyB8(
if(breakWhile) KXA)i5z
break; l@/kPEh
aC Lg~g4
y{I[}$k
//count++; 8 E+C:"
//if(count>4) 8Pr7aT:,
// siteStop(); #L= eK8^e
} fy>And*
bok 74U]
r5da/*G/O
System.err.println("文件下载结束！"); z/&a\`DsU
} v[DbhIXU
catch(Exception e){e.printStackTrace ();} *[~o~e/YCb
} C5PBfn<j
nC.2./OwMf
!v4j`A;%
//获得文件长度 bKJ7vXC05
public long getFileSize() yO,`"Dc_0
{ {r2|fgi
int nFileLength = -1; zpr@!76
try{ o"}&qA;
URL url = new URL(siteInfoBean.getSSiteURL()); n.XhK_6n]M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4J 51i*`
httpConnection.setRequestProperty("User-Agent","NetFox"); A1t~&?
pvQK6r
HGQ?(2]8$
int responseCode=httpConnection.getResponseCode(); ^8l3j4
if(responseCode>=400) C"^hMsU8
{ X8SRQO^
processErrorCode(responseCode); r{2].31'
return -2; //-2 represent access is error V52C,]qQH
} ie~fQ!rf
hk!,
[H:GKhPC`
String sHeader; sqpOS!]
, 64t
]baaOD$Z
for(int i=1;;i++) 1LId_vJtJ
{ m_Ac/ctf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FJ(B]n[>
//Utility.log(in.readLine()); oYh<k
sHeader=httpConnection.getHeaderFieldKey(i); [+MX$y
if(sHeader!=null) .i&ZT}v3
{ $K_YC~
if(sHeader.equals("Content-Length")) |~bR.IA
{ DMcxa.Sd!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W aGcoj
break; X})Imk7&E
} q&Tn>B
} H~dHVQtJZ
else =Wk/q_.
break; ^g-t#O lD?
} zIm_7\e
} J1]w*2
catch(IOException e){e.printStackTrace ();} N>pmhskN?
catch(Exception e){e.printStackTrace ();} H1%[\X?=
g?[&0r1
Ph+X{|
Utility.log(nFileLength); oAZF3h]po
lHKf#|
k8 ;uC~L
return nFileLength; ;64mf`
} (YYj3#|
8lWH=kA\
:9F''f$AP
//保存下载信息（文件指针位置） m&`(pf4A
private void write_nPos() qQxA@kdd
{ bH\C5zt6(
try{ hP1 l v7P
output = new DataOutputStream(new FileOutputStream(tmpFile)); Vp]D
output.writeInt(nStartPos.length); C3\E.u?
for(int i=0;i<nStartPos.length;i++) "7yNKO;W
{ &`yOIX-H_
// output.writeLong(nPos); 5`E`Kb+@
output.writeLong(fileSplitterFetch.nStartPos); )v52y8G-p
output.writeLong(fileSplitterFetch.nEndPos); 4j@i%
} 5K ,#4EOV
output.close(); IObx^N_K
} _}e7L7B7g
catch(IOException e){e.printStackTrace ();} fzS`dL5,W
catch(Exception e){e.printStackTrace ();} mGe|8In
} @1qdd~B}
9:%n=URd
`D)Lzm R
//读取保存的下载信息（文件指针位置） ,]Ro',A&
private void read_nPos() (/SGT$#8
{ jWXR__>.
try{ %0yS98']g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k6O.H
int nCount = input.readInt(); I%9bPQ
nStartPos = new long[nCount]; SY'2A)
nEndPos = new long[nCount]; x*h?%egB!p
for(int i=0;i<nStartPos.length;i++) [Y$5zeA
{ 3duG.iUlL
nStartPos = input.readLong(); Zn@W7c,_I
nEndPos = input.readLong(); l@N;sI<O-
} OQ(D5GR:4
input.close(); o#xgrMB
} LZM,QQ
catch(IOException e){e.printStackTrace ();} !8Z2X!$m{<
catch(Exception e){e.printStackTrace ();} .73zik
} hhpv\1h#
G[3k
6x_T@
private void processErrorCode(int nErrorCode) 8M^wuRn
{ L6:W'u^
System.err.println("Error Code : " + nErrorCode); F&QTL-pQW
} 3ar=1_Ar
aqs%m (
{)V?R
//停止文件下载 >*dQqJI
public void siteStop() kDzj%sm!
{ *me,(C
bStop = true; WY+(]Wkao
for(int i=0;i<nStartPos.length;i++) LY-lTr@A^
fileSplitterFetch.splitterStop(); }iilzE4oH#
"v(G7*2
a`H\-G
} B(j02<-
} 8FzHNG
//负责部分文件的抓取 ~->Hlxze'K
**FileSplitterFetch.java _i3i HR?
*/ tu\mFHvlg
package NetFox; %won=TG8
LBiowd[
m|pTn#*`
import java.io.*; YC]PN5[1!
import java.net.*; vd}*_d
GS\%mPZ
|9>*$Fe"
public class FileSplitterFetch extends Thread { ajn-KG!A
}A{_L6qx
of9q"h
String sURL; //File URL "7Eo>g
long nStartPos; //File Snippet Start Position R? O-x9
long nEndPos; //File Snippet End Position 8HMo.*Ti9
int nThreadID; //Thread's ID 3p=vz'
boolean bDownOver = false; //Downing is over rdO@X9z
boolean bStop = false; //Stop identical '_B_&is
FileAccessI fileAccessI = null; //File Access interface ]o-Fi$h!
7zD- ?%
* R%.a^R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6Wj@r!u
{ JE0?@PI$
this.sURL = sURL; x6LjcRS|
this.nStartPos = nStart; KNy`Lj)VPY
this.nEndPos = nEnd; Hu[]h]
nThreadID = id; ;}LJh8_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RfKc{V
} `f@{Vcr%i
%drJ p6n%
ibvJWg
public void run() {G]?{c)"
{ Aj,]n>{
while(nStartPos < nEndPos && !bStop) ],n%Xp
{ MDk*j,5V
+%P t_
JwZ?hc
try{ TfJL+a0
URL url = new URL(sURL); OCCEL9d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EYG"49 c
httpConnection.setRequestProperty("User-Agent","NetFox"); ;4,'y
String sProperty = "bytes="+nStartPos+"-"; tWm>j
httpConnection.setRequestProperty("RANGE",sProperty); huz86CO
Utility.log(sProperty); T?>E{1pS
PdT83vOCE
UxyY<H~Wx
InputStream input = httpConnection.getInputStream(); dY8(nQG
//logResponseHead(httpConnection); t\8&*(&3F
C1d 04Q
'Q5&5UrBr
byte[] b = new byte[1024]; VBM/x|'
int nRead; J{d(1gSZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UR}kB&t
{ i^WIr h3a
nStartPos += fileAccessI.write(b,0,nRead); 4IZlUJ?j+c
//if(nThreadID == 1) )R~aA#<>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ! ao6e
} Pey//U
\<ZLoy_
{7qA&c=
Utility.log("Thread " + nThreadID + " is over!"); <s_=-" il
bDownOver = true; =`-|&
//nPos = fileAccessI.write (b,0,nRead); =+<d1W`>0
} u,eZ6
catch(Exception e){e.printStackTrace ();} #4><r.v3
} Nsn~@.UuSW
} b$Ln}<
fD{II+T
tjj^O%SV<
//打印回应的头信息 &1_U1
public void logResponseHead(HttpURLConnection con) FPF6H puV
{ g`n;R
for(int i=1;;i++) M'q'$)e
{ G+VD8]!K1
String header=con.getHeaderFieldKey(i); ]*3:DU
if(header!=null) "mOI!xf@a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x`2| }AP(
Utility.log(header+" : "+con.getHeaderField(header)); `}gdN};
else 4=xq:Tf
break; "b]#MO}P
} FQROK4x%"
} o2aM#Q
94Ud@F9d5
Hd%!Nt\u
public void splitterStop() y])).p P
{ DL{R|3{N
bStop = true; / +1{
} P]Xbjs<p
1CkdpYjsj
1{Jb"
} F~6#LT
j)Y[4 ^k^
gRAC d&)
/* ` H XEZ|
**FileAccess.java e3v5,.
*//文件访问(定位，写) vc8?I."?
package NetFox; W8]V
import java.io.*; PK4`5uT
'eyJS`
Km!nM$=k
public class FileAccessI implements Serializable{ R*9NR,C
wAFW*rO5o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v$Uhm</|19
RandomAccessFile oSavedFile; `ZMK9f:
long nPos; 'e@=^FC
_dU8'H
26L~X[F
public FileAccessI() throws IOException MR$>!Nlp
{ O>c$sL0g
this("",0); $*\L4<(
} R?pRxY
!^y y0`k6
/YH`4e5g
public FileAccessI(String sName,long nPos) throws IOException +7U
{ nX^1$')gp
oSavedFile = new RandomAccessFile(sName,"rw"); l?8)6z#Zl
this.nPos = nPos; L9FHgl?
oSavedFile.seek(nPos); hO#t:WxFI
} he$XLTmr:
V*RdDF7
}T.?c9l X
public synchronized int write(byte[] b,int nStart,int nLen) ?D|\]0eN
{ k6(r !mc
int n = -1; h2w}wsb0l
try{ C4\,z\Q
oSavedFile.write(b,nStart,nLen); 9o0!m Cq
n = nLen; j U[ O
} ys'T~Cs
catch(IOException e) @hif$
{ LA%bq_>f
e.printStackTrace (); VK:8 Nk_y
} AIRr{Y
FT89*C)oD
.lNs4e
return n; !bU\zH
} Xsuwa-G!5~
z0bJ?~w,
@;:>GA
} gSt`%
uD9|.P}
*7$P]
/* 55Gtp\L
**SiteInfoBean.java z42F,4Gk
*/ 7&B$HZ
package NetFox; &dR=?bz-A
iv&v8;B
q,%:h`t\
public class SiteInfoBean { cz/Q/%j$/
z[EFQ^*>
yT8=l"-[G
private String sSiteURL; //Site's URL +jP~s
private String sFilePath; //Saved File's Path WYrI|^[>
private String sFileName; //Saved File's Name 6#e::GD
private int nSplitter; //Count of Splited Downloading File lfN~A"X
JC#>Td
.S?pG_n]f
public SiteInfoBean() 89~ =eY
{//nSplitter的缺省值为5 |=dC )Azs
//default value of nSplitter is 5 f)Xr!7
this("","","",5); <F=9*.@D
} 1HT_
E?)656F[
mQ~:Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W# US#<9Y
{ Te,$M3|
sSiteURL= sURL; 9QC.TG@
sFilePath = sPath; kA wNly
sFileName = sName; i38[hQR9a
this.nSplitter = nSpiltter; [KJ q
q,>?QBct*
YDC&u8
} ZD>a>]
TX [%(ft
qMYe{{r
public String getSSiteURL() 8,"yNq
{ x_#-tB
return sSiteURL; LiQgR 6j
} I5m][~6.?
~b~2 >c9
*^%*o?M~
public void setSSiteURL(String value) zj{r^D$
{ 2&!bfq![
sSiteURL = value; .L6Zm U
} .;7> y7$*
-O!/Jv"{,[
rN)V[5R#M
public String getSFilePath() {a(&J6$VE
{ "&.S&=FlI
return sFilePath; 9=X)ung9
} LE6.nmvS
^' M>r(t
q`NXJf=sc
public void setSFilePath(String value) {'En\e
{ Q]/Uq~m C
sFilePath = value; cD|Htt"
} M<PIeKIEB
"KX=ow#z|
IuF_M<d,
public String getSFileName() Nes=;%&]G
{ kX`[Y@nUN
return sFileName; )0 W`
} 2{Vcb
VZ& A%UFC
'(GiF
public void setSFileName(String value) -s|8<A||"
{ J(4"S o_
sFileName = value; d?AlI
} Sq\(pfvo
NEt1[2X%
2dp>Z",
public int getNSplitter() wr(*?p]R
{ U6E\AvbRn
return nSplitter; 0|&\'{
} 8lF\v/vN
1NQbl+w#I
lKWPTCU
public void setNSplitter(int nCount) ~S,p?I
{ zaTb~#c_
nSplitter = nCount; @yd4$Mv8%
} ]?O2:X
} @Jm7^;9/
)a@k]#)Skm
5tjP6Z`!9`
/* W&(k!6<x
**Utility.java !-`Cp3gqHr
*/ *]hBGr#6
package NetFox; 7>iU1zy
g V5zSudW
D8&`R
public class Utility { ,Ys"W x
3pf[M{dG
l3Njq^T
public Utility() y[B>~m8$
{ HK\~Qnq
~'37`)]z
=K'cM=WM6
} QrO\jAZ{Ag
cdqB,]"
//线程睡眠 X\EVTd)@
public static void sleep(int nSecond) 2(5ebe[
{ 1f",}qe;
try{ }_=eT]
Thread.sleep(nSecond); su*Pk|6%
} 'lHdOG
catch(Exception e) (=D&A<YX
{ lj+u@Z<xA
e.printStackTrace (); W>-Et7&2
} w 4[{2
} oh#\]c\f
8-<:i
//日志 "-@[R
public static void log(String sMsg) ()&~@1U
{ }neY<{z
System.err.println(sMsg); @(r/dZc
} hI9
__mF?m
BIuK @$
public static void log(int sMsg) \%UkSO\nO3
{ V#VN%{
System.err.println(sMsg); 87hq{tTs]
} &0f5:M{P
} vfVj=DYj
9z6XF]A
y;/VB,4V
/* (o3 Iy
**TestMethod.java jKt7M>P
*/ N('&jHF
package NetFox; n:MdYA5,m
2eMTxwt*S
/Q,mJ.CnSR
public class TestMethod { J:V?EE,\-
Sa2>`":d
6{=\7AY
public TestMethod() /SYw;<=
{ ///xx/weblogic60b2_win.exe @)J+,tg/7
try{ M4as
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;!(<s,c#:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9(QJT}qC
SiteFileFetch fileFetch = new SiteFileFetch(bean); j?'GZ d"B
fileFetch.start(); .Wjs~0c
} H;RwO@v
catch(Exception e){e.printStackTrace ();} "AE5 V'
Omd .9
]+X@ 7
} t.mVO]dsj
-GxaV #{
B}^w_C2
public static void main(String[] args) 4?B\O`sy.
{ AK@9?_D
new TestMethod(); c/sC&i;%O
} dAuJXGo
} p5G?N(l
点击下载更多相关资料