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)); 2!w5eWl,
} Juhi#&`T
for(int i=0;i<nEndPos.length-1;i++) #1-2)ZO.
{ _EusY3q
nEndPos = nStartPos[i+1]; |}FK;@'I6
} rnkq.
nEndPos[nEndPos.length-1] = nFileLength; .uoQ@3
} 7A@iu*t
} b|rMmx8vA
dj;Zzt3
ZH1W#dt`[
//启动子线程 3iKy>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \ZOH3`vq
for(int i=0;i<nStartPos.length;i++) lDWg%pI+
{ +WH|nV~lQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,A{'lu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *GGiSt
nStartPos,nEndPos,i); *EB`~s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^D}]7y|fm
fileSplitterFetch.start(); e@`"V,i
} ZCcKY6b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sOf;I]E|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1DTA Dh0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t_+Xt$Q7C
nEndPos = " + nFileLength); ='\Di '*
// fileSplitterFetch[nPos.length-1].start(); ./KXElvQ%
TV['"'D&i
cu@i;Hb@
//等待子线程结束 4/Mi-ls_
//int count = 0; IAlX^6s*
//是否结束while循环 1KI,/H"SY
boolean breakWhile = false; ~{xm(p
Dp8`O4YC
O'WBO"
while(!bStop) y8!#G-d5
{ lQq&tz,
write_nPos(); k$NNpv&;d
Utility.sleep(500); 3= q,k<=L
breakWhile = true; J8;lG
a*D])Lu[
XMLJX~
for(int i=0;i<nStartPos.length;i++) \y^Ho1Fj
{ p$:ERI
if(!fileSplitterFetch.bDownOver) }5nVZ;
{ j-CSf(qIj
breakWhile = false; v0 3
break; ^'Z?BK
} O/N@Gz[g%
} V~~4<?=A
if(breakWhile) >Av[`1a2F
break; p-S&Wq
45qSt2
K.R4.{mo
//count++; nG~#o
//if(count>4) Rn4Bl8z'>
// siteStop(); jMAZ4M
} sx]kH$
?nwFc3qw
[#3*R_#8R
System.err.println("文件下载结束！"); Rt6(y #dF
} \I[f@D-J
catch(Exception e){e.printStackTrace ();} Osk'zFiL<
} d'okXCG
gR]NH
xl]1{$1M
//获得文件长度 aQTISX;
public long getFileSize() dsiQ~ [
{ Pc:5*H
int nFileLength = -1; uexm|5|
try{ DDwj[' R
URL url = new URL(siteInfoBean.getSSiteURL()); A|90Ps
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :p|wo"=@Ge
httpConnection.setRequestProperty("User-Agent","NetFox"); y+"6Y14
';>A=m9(4%
Bokpvd-c7
int responseCode=httpConnection.getResponseCode(); +5k^-
if(responseCode>=400) |Q\O% cb
{ VUF$,F9
processErrorCode(responseCode); h't!1u
return -2; //-2 represent access is error 4[P]+Z5b+
} j]X$7
tEbR/?,GI
)/vse5EG+
String sHeader; Ig{ 3>vB
"rJJ~[Y
x&4gy%b
for(int i=1;;i++) O'L9 s>B
{ $[*QsU%%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CwL8-z0 Jn
//Utility.log(in.readLine()); ulAOQGZ
sHeader=httpConnection.getHeaderFieldKey(i); 6 *GR_sMm
if(sHeader!=null) Ks>l=5~v|
{ S5(VdMd"^
if(sHeader.equals("Content-Length")) iKVJ c=C
{ t~0!K;nn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <} BuU!
break; k7cM.<s!
} QO;OeMQv%
} #<k L.e[
else G<_<j}=
break; t)__J\xF
} -L6YLe%w
} N0POyd/rL
catch(IOException e){e.printStackTrace ();} D_D76
catch(Exception e){e.printStackTrace ();} !*1Kjg3
>DSD1i+N
d&x #9ka
Utility.log(nFileLength); 5?=haGn
a^xt9o`
y~Ts9AE
return nFileLength; "R5! VV
} >K@Y8J+e#
.gP}/dj
;+3XDz v
//保存下载信息（文件指针位置） 7+2DsZ^6MW
private void write_nPos() KM:k<pvi
{ 8TH fFL
try{ XN Gw@$
output = new DataOutputStream(new FileOutputStream(tmpFile)); j-%@A`j;
output.writeInt(nStartPos.length); RO!em~{D*
for(int i=0;i<nStartPos.length;i++) S@^o=B]]
{ Wq"5-U;:w
// output.writeLong(nPos); YA:!ULzR*
output.writeLong(fileSplitterFetch.nStartPos); \nbGdka
output.writeLong(fileSplitterFetch.nEndPos); "+sl(A3`U
} A(84cmq!q
output.close(); `ttqgv\
} {Yc#XP
catch(IOException e){e.printStackTrace ();} y8e'weK
catch(Exception e){e.printStackTrace ();} s)BB(vQ]6
} /YrBnccqD
q?0&&"T}
=&,<Co1hF
//读取保存的下载信息（文件指针位置） +aoenUm5
private void read_nPos() eR|u']Em>T
{ d#vo)>
try{ RqU^Q*/sF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?igA+(.
int nCount = input.readInt(); G}V5PEF]`
nStartPos = new long[nCount]; ~bnyk%S o
nEndPos = new long[nCount]; VoG:3qN
for(int i=0;i<nStartPos.length;i++) 69iY)Ob/
{ cME|Lg(J$
nStartPos = input.readLong(); {?YBJnG}x
nEndPos = input.readLong(); u_*DS-
} (O-.^VV
input.close(); $TZjSZ1w
} #e*jP&1S
catch(IOException e){e.printStackTrace ();} 9%& =n
catch(Exception e){e.printStackTrace ();} ?K!^[aO}=
} /t|Lu@&:Xo
HOSt0IHzty
.EB'n{zxd
private void processErrorCode(int nErrorCode) GC3WB4iY@U
{ SCq:jI
System.err.println("Error Code : " + nErrorCode); }v4T&/vt-
} I3^}$#>
VOkSR6
Gv\:Agi
//停止文件下载 ;^f ;<
public void siteStop() CBKLct>
{ );!IGcgF
bStop = true; <.knM
for(int i=0;i<nStartPos.length;i++) AV]7l}-
fileSplitterFetch.splitterStop(); ; nc3O{rU
nAT,y9&
Q^}Ib[
} 6^VPRp
} L )53o!
//负责部分文件的抓取 (kmrWx= $
**FileSplitterFetch.java !4vepa}Y
*/ n]x%xnt
package NetFox; 8~j1
`)TuZP_)
c_Lcsn
import java.io.*; !e?2 x@J
import java.net.*; ]y\Wc0q
_L% =Q ulu
pZ)N,O3
public class FileSplitterFetch extends Thread { FByA4VxB
\<u
+cwuj
String sURL; //File URL 8Xx4W^*_
long nStartPos; //File Snippet Start Position 5MHcgzyp
long nEndPos; //File Snippet End Position #D ]P3
int nThreadID; //Thread's ID ^|UD&6 dx
boolean bDownOver = false; //Downing is over KbGz3O'u
boolean bStop = false; //Stop identical Ux-i iH#s
FileAccessI fileAccessI = null; //File Access interface S.R|Bwj}(Y
}'WEqNuE
9,cMb)=0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n%K^G4k^
{ rGmxK|R
this.sURL = sURL; z]HaE|j}S
this.nStartPos = nStart; 1{-yF :A
this.nEndPos = nEnd; bR'UhPs-8;
nThreadID = id; 3XSfXS{lwP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oYAHyCkVq
} %Xe 74C"
` #; "
&j?+%Y1n@
public void run() S~hoAl"xb/
{ i5#4@ 4aC
while(nStartPos < nEndPos && !bStop) MG:eI?G/'
{ sH51 .JG
|crm{]7X
L/xTW
try{ NiBly
URL url = new URL(sURL); [79iC$8B|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;iO5 8S3
httpConnection.setRequestProperty("User-Agent","NetFox"); k*K.ZS688
String sProperty = "bytes="+nStartPos+"-"; uJSzz:\
httpConnection.setRequestProperty("RANGE",sProperty); e]*@|e4b
Utility.log(sProperty); UW'@3#<?
%\] x}IC
trz&]v=:
InputStream input = httpConnection.getInputStream(); |a!]Iqz"N
//logResponseHead(httpConnection); @kWRI*m
z#*>u
Oh5aJ)"D
byte[] b = new byte[1024]; #c$z&J7e
int nRead; G]zyx"0Sqb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j1O_Az|3
{ "0aJE1)p:
nStartPos += fileAccessI.write(b,0,nRead); oH;9s-Be
//if(nThreadID == 1) 5pH6]$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u$<>8aMei
} ZVz`g]
Eg(.L,dj
6PT"9vR`)
Utility.log("Thread " + nThreadID + " is over!"); I~Q G
bDownOver = true; <.=-9O6
//nPos = fileAccessI.write (b,0,nRead); bKt4
} I9L7,~s
catch(Exception e){e.printStackTrace ();} ~oz??SX
} 3c+ps;nh
} Ya;y@44
IG90mpLX
9`td_qh
//打印回应的头信息 )Wy:I_F351
public void logResponseHead(HttpURLConnection con) ttA'RJ
{ &AnWMFo
for(int i=1;;i++) p^)w$UL}}
{ b6!7j
String header=con.getHeaderFieldKey(i); 7O,!67+^~
if(header!=null) e.WKf,e"X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NH<~BC]I
Utility.log(header+" : "+con.getHeaderField(header)); W>(w&k]%B
else k [iT']
break; $]gflAe2
} Gq-~zmg
} (,D:6(R7t
Xi0fX$-,
g(dReC
public void splitterStop() ej,R:}C%`
{ Y)2#\ F
bStop = true; (qzBy \\p
} '7 t:.88
2 ZyO
oQ}K_}{>
} nh+Hwj#(x
oSLm?Lu
uyvjo)T
/* o(yyj'=(
**FileAccess.java Id=V\'$o
*//文件访问(定位，写) 0ax;Q[z2
package NetFox; ?\$6"c<G
import java.io.*; 6w~Cyu4Ov
1E=E ?$9sg
7Q9| P?&:z
public class FileAccessI implements Serializable{ }$b!/<7FD
S0`u!l89(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6+4SMf3
RandomAccessFile oSavedFile; <c$rfjM+JU
long nPos; iKu4s
#,h0K
W3jwc{lj
public FileAccessI() throws IOException c7D{^$L9v
{ z9E*1B+
this("",0); <R?S
} u.Tknw-X
s8dP=_ `
EHK+qrym
public FileAccessI(String sName,long nPos) throws IOException :LCyxLI
{ {DZ xK(
oSavedFile = new RandomAccessFile(sName,"rw"); P!I Lji!
this.nPos = nPos; xlH3t&i7
oSavedFile.seek(nPos); uU=!e&3
} Ygc|9}
@VQ<X4Za
l{*Ko~g
public synchronized int write(byte[] b,int nStart,int nLen) _*Ej3=u
{ e.fxB
int n = -1; ^!z(IE'
try{ MT6"b
oSavedFile.write(b,nStart,nLen); -Jt36|O
n = nLen; Z!3R
} 8nwps(3
catch(IOException e) +J#8wh
{ 5fRrd;
e.printStackTrace (); B$qTH5)W
} 5?[hr5E.E
>+DMTV[O
I%NeCd
return n; +S WtHj7e
} ]Ljb&*IEj
Q\>mg*79
X#HH7V>
} nuVux5:
%y7ZcH'
K0D|p$v
/* zB/VS_^^W:
**SiteInfoBean.java =~5N/!
*/ 5H1N]v+
package NetFox; _l+C0lQl=
tEt46]{
O*.n;_&
public class SiteInfoBean { #M4LG; B
5~ZzQG
qOIVuzi*
private String sSiteURL; //Site's URL w@Asz9Lq%
private String sFilePath; //Saved File's Path Z}{]/=h
private String sFileName; //Saved File's Name Xppv
private int nSplitter; //Count of Splited Downloading File Uf MQ?(,
qoZ)"M
,.h@tN<C
public SiteInfoBean() OZC yg/K
{//nSplitter的缺省值为5 jFip-=T{4
//default value of nSplitter is 5 e<(6x[_
this("","","",5); o1"N{Eu
} I@\D tQZ
R+_!FnOJ
KuW>^mF(I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )FPn_p#3]
{ q`?M+c*F
sSiteURL= sURL; #eX<=H]
sFilePath = sPath; G"tlJ7$myQ
sFileName = sName; V.6pfL
this.nSplitter = nSpiltter; kKjcW` [
iSUu3Yv,_m
UWhJkJsX
} 'IT]VRObP
~ch%mI~
,fqM>Q
public String getSSiteURL() L62%s[
{ K|OPtYeb
return sSiteURL; z 2jC48~
} f/s"2r
UR9\g(
,7k-LAA
public void setSSiteURL(String value) ALcPbr
{ z"mpwmv5
sSiteURL = value; Go^TTL
} ><>%;HZ
\q3ui}-9
qozvNJm)
public String getSFilePath() y. 1F@w|
{ 2i;ox*SfpU
return sFilePath; cD=IFOB*GD
} NUJ $)qNA
|i#06jIq
=FI[/"476
public void setSFilePath(String value) bC~I}^i\
{ 5pC}ZgEa<
sFilePath = value; t`{T:Tjc
} $4~Z]-38#A
G "!v)o
?L0k|7
public String getSFileName() 9_,f)2)~W
{ 1Lk(G9CoY
return sFileName; ez.a
} ;<thEWH;Y
W amOg0
)B)f`(SA"<
public void setSFileName(String value) t1"#L_<e
{ hvQXYo>TZx
sFileName = value; "^!y>]j#A
} *,%$l+\h
u`.)O2)xU
gujP{Z
public int getNSplitter() &xhwOgI#,
{ ZO%iyc%
return nSplitter; Hb::;[bm:
} LkP :l
Xx%<rsA>F
)J0h\ky
public void setNSplitter(int nCount) Cl!(F6K*
{ %?aq1 =B
nSplitter = nCount; 2H0BNrYM
} <<E9MIn_
} E`V\/`5D
;,e16^\' &
B /w&Lo
/* F?05+
**Utility.java #p55/54ZI
*/ iU37LODa2T
package NetFox; #.[eZ[
KX7fgC
B2P@9u|9
public class Utility { CaO-aL
P9f`<o
2<y9xvp
public Utility() @2a!T03
{ %2\tly!{ %
z7gX@@T
CfSP*g0rW
} 3Jt# Mp
vJ=Q{_D=\
//线程睡眠 CswKT9
public static void sleep(int nSecond) QIevps*
{ 'L-DMNxBr
try{ M@<9/xPS
Thread.sleep(nSecond); f,Dic%$q
} X(X[v]
catch(Exception e) ,Kl?-W@
{ rF"p7
e.printStackTrace (); uOJqj{k_."
} Iv*\8?07)
} FVBAB>
R3l{.{3p2
//日志 h9CTcWGt
public static void log(String sMsg) ^V#,iO9.-
{ uC#@qpzy
System.err.println(sMsg); /]5*;kO`
} M<n'ZDK`W
Z+J4q9^$
\`xlD&F@U
public static void log(int sMsg) %)?jaE}[
{ LybaE~=
System.err.println(sMsg); geqP.MR
} A;RV~!xx
} ^bfZd
Z[d13G;
'ScvteQ
/* L 1!V'Hm{
**TestMethod.java e@anX^M;
*/ )X[2~E
package NetFox; / +%
X(MS!RV
'!8-/nlv1
public class TestMethod { ocJG4#
RK &>!^
*wj5(B<y
public TestMethod() 16~E
{ ///xx/weblogic60b2_win.exe z]+L=+,,
try{ S7Ty}?E@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o!KDeY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }UB@FRPF
SiteFileFetch fileFetch = new SiteFileFetch(bean); S#y[_C?H
fileFetch.start(); G%t>Ll``C
} PC<_1!M]
catch(Exception e){e.printStackTrace ();} @r/~Y]0Ye5
qJrKt=CE
3u$1W@T(
} CssE8p>"F
[i ~qVn2vT
?zm]KxIC
public static void main(String[] args) lYJSg70P
{ oq+w2yR
new TestMethod(); 3cL iZ%6^
} adX"Yg!`{c
} !=,Y=5M,
点击下载更多相关资料