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+L! A
} Q/< $ (Y
for(int i=0;i<nEndPos.length-1;i++) )P$ IXA\
{ Nk7Q
nEndPos = nStartPos[i+1]; P"- ,^?6
} X\h]N
nEndPos[nEndPos.length-1] = nFileLength; p5*i d5
} ?znSA >
} AVi|JY)>
cD{[rI E3
r6^DD$X
//启动子线程 ]Z~H9!%t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `0sa94H1[
for(int i=0;i<nStartPos.length;i++) IlwY5iL
{ E_xpq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mFvw s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H}:apRb
nStartPos,nEndPos,i); i$ Zhk1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xdjxt?*
fileSplitterFetch.start(); 0n1y$*I4
} ~<|xS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r`" ?K]rI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [E=t{&t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r:u5+A
nEndPos = " + nFileLength); }ulFW]A^7
// fileSplitterFetch[nPos.length-1].start(); /$B<+;L!#
wZ*m
vXyaOZ
//等待子线程结束 A }dl@
//int count = 0; ;'nu9FU*O
//是否结束while循环 ?bbguwo~F
boolean breakWhile = false; IH{g-#U
dLv\H&
ecr pv+
while(!bStop) qgu.c`GmW
{ .>&kAf.
write_nPos(); u{I)C0
Utility.sleep(500); B&tl6?7h
breakWhile = true; $ZE OE8.\
[*,`a]z-Q
27;*6/>,
for(int i=0;i<nStartPos.length;i++) &!~q#w1W-5
{ e`Yx]3;u(
if(!fileSplitterFetch.bDownOver) )u<sEF
{ Lx2.E1?@
breakWhile = false; Y(<>[8S m
break; u+S*D\p<`
} W[+E5I
} oZ!rK/qoA
if(breakWhile) 4j/8Otn
break; \p.ku%{
$NqT={!
MvObx'+
//count++; !k&<
//if(count>4) xAsbP$J:
// siteStop(); Ww@Rewo
} IX-ir
VTD'D+t
m\j'7mZ1
System.err.println("文件下载结束！"); 6N6d[t"
} t+ Fm?
catch(Exception e){e.printStackTrace ();} xez~Yw2
} Io| 72W}rg
y\Zx{A[
8j8FQ!M
//获得文件长度 3TO$J
public long getFileSize() !x|Ok'izDL
{ *y7^4I-J
int nFileLength = -1; h@l5MH=|%
try{ ]Y:|%rvVH
URL url = new URL(siteInfoBean.getSSiteURL()); Haiuf)a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #m|AQr|
httpConnection.setRequestProperty("User-Agent","NetFox"); 6f0 WN
NO"=\Zn6
O']-<E`1k
int responseCode=httpConnection.getResponseCode(); -cEjB%Neo
if(responseCode>=400) )mJl-u[0+
{ 4mUQVzV
processErrorCode(responseCode); YG<?|AS/
return -2; //-2 represent access is error l[.RnM[v
} 6wfCC,2
i9uJ%nd:
T[L
String sHeader; HBeOK
f0}+8JW5h
zR">'bM:
for(int i=1;;i++) 9 *Q/3|
{ b4i=eI8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PWx2<t<;9
//Utility.log(in.readLine()); *r$(lf
sHeader=httpConnection.getHeaderFieldKey(i); StA5h+[m
if(sHeader!=null) $ ^m_M.1
{ jbGP`b1_
if(sHeader.equals("Content-Length")) KE6[u*\
{ H/YZwDx,i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Il>!C\hU
break; }5FdX3YR
} \A Y7%>
} C4]vq+
else h)fi9
break; z^O>'9#
} jv?`9{-
} T)qD}hl
catch(IOException e){e.printStackTrace ();} ~~]L!P
catch(Exception e){e.printStackTrace ();} PL[7|_%
1\TXb!OtL
kuqf(
Utility.log(nFileLength); RL SP?o2J
+m]$P,yMt
bncIxxe
return nFileLength; ^LX1&yT@
} O#uTwnW
H~e;S#3_v
Y }aa6
//保存下载信息（文件指针位置） :"|}oKT%mP
private void write_nPos() ci <`*>l
{ =4 36/O`K
try{ sTU`@}}
output = new DataOutputStream(new FileOutputStream(tmpFile)); =6Ihk
output.writeInt(nStartPos.length); b7p&EK"Hm
for(int i=0;i<nStartPos.length;i++) z;x$tO
{ ]]J2#mN:n
// output.writeLong(nPos); ehPrxIyC
output.writeLong(fileSplitterFetch.nStartPos); eI/9uR%
output.writeLong(fileSplitterFetch.nEndPos); Jo1n>Mo-j
} X~T"n<:a>
output.close(); Yw vXSA
} C2<!.l
catch(IOException e){e.printStackTrace ();} '!I^Lfz-Z
catch(Exception e){e.printStackTrace ();} FcB]wz
} #%rXDGDS
rp (nGiI
c~K^ooS-
//读取保存的下载信息（文件指针位置） PTXy:>]M
private void read_nPos() TLU^ad#9E
{ _p"nR
try{ DP6M4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8A~5@
int nCount = input.readInt(); b7^VWX%
nStartPos = new long[nCount]; Y.$'<1
nEndPos = new long[nCount]; FY|.eY_7 {
for(int i=0;i<nStartPos.length;i++) y'(l]F1]
{ PF+v[h;,
nStartPos = input.readLong(); "qYPi
nEndPos = input.readLong(); G'{$$+U^K
} mp:%k\cF|
input.close(); 7y1J69IK
} mzLDZ#=b
catch(IOException e){e.printStackTrace ();} I9-vV>:z
catch(Exception e){e.printStackTrace ();} Y9F!HM-`
} KWq7M8mq
n[H3b}
hiZE8?0+~N
private void processErrorCode(int nErrorCode) eQbDs_
{ q90eB6G0g
System.err.println("Error Code : " + nErrorCode); Mhc!v, D$
} ~pWbD~aeg
QqA~y$'ut
"T|%F D&[
//停止文件下载 !/^i\)j>](
public void siteStop() *,A?lX,9A
{ EbZRU65J}O
bStop = true; Sp3?I2 o
for(int i=0;i<nStartPos.length;i++) q{gt2OWqX
fileSplitterFetch.splitterStop(); mf^=tZ
B`3RyM"J@
:Y`cgi0vkd
} ![YLY&}s
} tt2`N3Eu\
//负责部分文件的抓取 { K'QE0'x
**FileSplitterFetch.java xL,Lb}){%
*/ ^R',P(@oL
package NetFox; -]\cUQ0
(\}>+qS[
^|M\vO
import java.io.*; TO7%TW{L
import java.net.*; !*_5 B'
v<c~ '?YzO
Bt[OGa(q
public class FileSplitterFetch extends Thread { &(UVS0=Dp,
K<'L7>s3lA
|-GmWSK_
String sURL; //File URL mZDL=p
long nStartPos; //File Snippet Start Position yNMnByg3?
long nEndPos; //File Snippet End Position *u^N_y
int nThreadID; //Thread's ID b0|q@!z>
boolean bDownOver = false; //Downing is over i>#[*.|P
boolean bStop = false; //Stop identical qfE>N?/
FileAccessI fileAccessI = null; //File Access interface ]@)T]
/*\pm!]._^
, v,mBYaU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <8nl}^d5
{ eJFGgJRIvF
this.sURL = sURL; ij i<+oul
this.nStartPos = nStart; d5mhk[p7\J
this.nEndPos = nEnd; *F|j%]k~
nThreadID = id; *NzHY;e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \,| Xz|?C
} >tTNvb5
G?e"A0,
[zmx
public void run() q{I,i(%m8
{ 22lC^)`TE
while(nStartPos < nEndPos && !bStop) SZW+<X
{ M il ![A1
+Gv{Apd"
,b!!h]t
try{ =@$G3DM
URL url = new URL(sURL); EooQLZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p""#Gbwj
httpConnection.setRequestProperty("User-Agent","NetFox"); ^c",!Lp}{
String sProperty = "bytes="+nStartPos+"-"; Mr'P0^^
httpConnection.setRequestProperty("RANGE",sProperty); /Ud<4j-
Utility.log(sProperty); LnZzY0
qd\5S*Z1
Cj^:8 ?%
InputStream input = httpConnection.getInputStream(); Gu} `X23
//logResponseHead(httpConnection); `|@#~
A;VjMfoB
&Ohm]g8{2
byte[] b = new byte[1024]; FRa@TN/Ic
int nRead; P9h]Bu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rrBu6\D
{ :l<)p;\
nStartPos += fileAccessI.write(b,0,nRead); r_/=iYYJ
//if(nThreadID == 1) _hT-5)1r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -+fbK/
} .XD7};g
d3Dw[4
~xI1@^r
Utility.log("Thread " + nThreadID + " is over!"); F)P"UQ!\
bDownOver = true; _cra_(b
//nPos = fileAccessI.write (b,0,nRead); cm^:3(yYX
} |^&n\vXv
catch(Exception e){e.printStackTrace ();} QH%Zbt2qS
} F&?55@b
} ?Ne@OMc
=\CJsS.
H}G=%j0
//打印回应的头信息 =*EIe z*.x
public void logResponseHead(HttpURLConnection con) 242dT/j
{ 7d&_5Tj:
for(int i=1;;i++) g3[Zh=+]E
{ P2J{Ml#
String header=con.getHeaderFieldKey(i); Exir?G}\
if(header!=null) O 1TJJ8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f+>l-6M+p
Utility.log(header+" : "+con.getHeaderField(header)); -1dbJ/)
else 05eth
break; Q(@/,%EF
} -<rQOPH%
} [KrWL;[1<
_ 4:@+{
ShXk\"
public void splitterStop() yh9fHN)F
{ u{Jv6K,
bStop = true; cI}qMc
} O^fg~g X
8\,|T2w,X
A)9[.fhx
} *Z0Y:"
6{h+(|.(
&0B<iO<f
/* / S
**FileAccess.java rGb7p`J
*//文件访问(定位，写) ~AbnksR
package NetFox; biwV7<
import java.io.*; #hinb[fQ
(_&W@:"z
4o,%}bo&
public class FileAccessI implements Serializable{ >:W7f2%8`
a[TR_uR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LW?Zd=
RandomAccessFile oSavedFile; LxqK@Q<B
long nPos; ,(aOTFQS
!'uLV#YEZ
>r Nff!Ow
public FileAccessI() throws IOException Y|ONCc
{ diXb8L7B;
this("",0); BR8W8nRb
} $HjKELoJ<
?Y6MC:l<
om3$=
public FileAccessI(String sName,long nPos) throws IOException J?/.|Y]e
{ O6rrv,+_L
oSavedFile = new RandomAccessFile(sName,"rw"); >dH5n$Gb
this.nPos = nPos; <^:e)W
oSavedFile.seek(nPos); g=eYl_P6
} NOOP_:(7H
`c 3IS5
8o' a
public synchronized int write(byte[] b,int nStart,int nLen) EJqzh i5
{ r()%s3$q
int n = -1; npcB+6
try{ uQy5t:!
oSavedFile.write(b,nStart,nLen); %9.] bd|%F
n = nLen; KX*Hev'K
} $`q8-+{
catch(IOException e) }@IRReQ
{ d~L`*"/)[
e.printStackTrace (); 1_JxDT,=>
} wg6![Uh
V\axOz!
.E!p
return n; }5n((7@X
} r,p6J7/lfS
nquKeH
*SkUkqP9z
} )tQG5.to
S@suPkQ<>
wn*z*
/* 2N]u!S;d
**SiteInfoBean.java W":is"
*/ muLt/.EZ
package NetFox; i4TU}.h8
\'( @{
5ug?'TOj'
public class SiteInfoBean { KMz\h2X
\=+s3p5N
\ iL&Aq}BO
private String sSiteURL; //Site's URL Qy ; M:q
private String sFilePath; //Saved File's Path ?DVO\Cp
private String sFileName; //Saved File's Name 1j*I`xZ
private int nSplitter; //Count of Splited Downloading File '[shY
_E5%Px5>L
QZufQRfr{
public SiteInfoBean() fgFBOpG%Gq
{//nSplitter的缺省值为5 '"}|'J
//default value of nSplitter is 5 rI&GM |
this("","","",5); rl)(4ad=
} 9GnNL I{
riI0k{
Z<a6U 3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *[*E|by
{ p},6W,f
sSiteURL= sURL; qB3{65
sFilePath = sPath; bhXH<=
sFileName = sName; .vRLK
this.nSplitter = nSpiltter; &J|3uY,'j
3j.Ft*SV
9GS<d.#Nvc
} Cna@3)_
dN>XZv
W38My j!
public String getSSiteURL() qF6YH
{ D={|&:`L e
return sSiteURL; bo&!oY#
} owe362q
k/nOz*
{! RW*B
public void setSSiteURL(String value) s-r$%9o5
{ Ah)OyO6
sSiteURL = value; *iF>}yhe
} W|=?-
7Z>u|L($m
GCrh4rxgg
public String getSFilePath() |0(Z)s,
{ b:7;zOtF
return sFilePath; @f0~a
} CAY^ `K!
c1wM"
aKaqi}IT
public void setSFilePath(String value) ".| 9h
{ >]"5K<-1
sFilePath = value; ~Dr/+h:^\
} @Z!leyam
[(tgoh/
tklU zv
public String getSFileName() JGZ,5RTq4-
{ xMtl<Na
return sFileName; io cr
} ro37H2^Ty
xkl'Y*
\Ja%u"DA
public void setSFileName(String value) ;9c3IK@
{ oUZwZ_yKW
sFileName = value; ) 0$7{3
} 4UoUuKzt
pRXA!QfO
W<;i~W
public int getNSplitter() +8[h&
{ @{.rDz
return nSplitter; aEX;yy*
} 1oo'\
3P/T`)V
r4NI(\gU
public void setNSplitter(int nCount) 5d|*E_yu
{ 7&NRE"?G
nSplitter = nCount; e~J% NU'&
} q=bJ9iJsq
} <(d^2-0
1*?IDYB
{#q<0l
/* .D^k0V
**Utility.java 2U>1-p&dn
*/ iUA2/ A
package NetFox; >;o^qi_$
*P:`{ZV7=W
[x!T<jJ
public class Utility { ,{itnKJC
.EH^1.|v
{^9,Dy_D
public Utility() PK3)M'[
{ ci5ERv`
2DTH|Yv
yt C{,g>
} bEbO){Fe
@Sub.z&T{
//线程睡眠 G#duZNBdc
public static void sleep(int nSecond) 60~{sk~E
{ *~4uF
try{ NNutpA}s
Thread.sleep(nSecond); 3-32q)8
} &4"(bZ:LO
catch(Exception e) Q(AOKp,F
{ 2b1LC!'U
e.printStackTrace (); ..<(HH2
} N3vk<sr@
} 'n4zFj+S
DXKk1u?Tq
//日志 3`#sXt9C
public static void log(String sMsg) jY>KF'y
{ 8<)[+@$0
System.err.println(sMsg); k4pvp5}%
} HJBUN1n
]lQhIf6)k
'4HwS$mW3
public static void log(int sMsg) U@D=.6\B
{ }'kk}2ej`
System.err.println(sMsg); ICq;jfML
} PKdM-R'Z
} o [ar.+[
\C}tK,79
:+]6SC0ql
/* I$qL=
**TestMethod.java a<!g*UVL0M
*/ F8b*Mt}p
package NetFox; `mw@"
W@"M/<r@/
QHMXQyr(
public class TestMethod { ~DqNA%Mb
o1zc`Ibd
K* [cJcY+
public TestMethod() 6gakopZO
{ ///xx/weblogic60b2_win.exe 'y-IE#!5
try{ HW.S~eLw*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +t.T+` EG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 56?U4wj7{
SiteFileFetch fileFetch = new SiteFileFetch(bean); jE2ziK
fileFetch.start(); J[LGa:``
} axU!o /m>
catch(Exception e){e.printStackTrace ();} aeSy,:
J>hl&J
seAkOIc
} sS5#Q
nkN]z ^j
EW2e k^
public static void main(String[] args) e;rs!I!Yw
{ y*Ex5N~JC
new TestMethod(); PK3T@Qv89
} +|#sF,,X4g
} 2U~oWg2P
点击下载更多相关资料