http断点续传简单实现（java)

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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)); @"h4S*U
} I@z@s}x>
for(int i=0;i<nEndPos.length-1;i++) prt(xr4@
{ qi~-<qW
nEndPos = nStartPos[i+1]; [(g2u@
} 2.</n}g
nEndPos[nEndPos.length-1] = nFileLength; zOA~<fhT
} J~J+CGT~2
} P<Z` 8a[
&ZMQ]'&
|wJdp,q R
//启动子线程 $bp$[fX(e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sqpo5~
for(int i=0;i<nStartPos.length;i++) ";`jS&"=
{ \IC^z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &Jb$YKt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IhK SwT
nStartPos,nEndPos,i); h}'Hst
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q=%W-
fileSplitterFetch.start(); $bKXP(
} E@otV6Wk[@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {S+?n[1r\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D=vw0Q_3Y3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #b&tNZ4!_
nEndPos = " + nFileLength); pam9wfP
// fileSplitterFetch[nPos.length-1].start(); |15!D
iku*\,6W
h{_\okC>
//等待子线程结束 2o9B >f&g
//int count = 0; SJX9oVJeZ
//是否结束while循环 `-CN\
boolean breakWhile = false; {HM[ )t0
Jlb{1B$7
<z%**gP~G
while(!bStop) &-o5lrq
{ lb9?Uc@
write_nPos(); irm4lb5
Utility.sleep(500); j7:r8? G
breakWhile = true; [*It' J^
:qqG%RB
nu+^D$ait
for(int i=0;i<nStartPos.length;i++) 3rFku"zT$
{ |xZu?)M4
if(!fileSplitterFetch.bDownOver) zJ(DO>,p&
{ " wT?$E
breakWhile = false; xv2c8g~vD
break; ^/}4M'[w
} cy(w*5Upu
} {T^D&i# o
if(breakWhile) bJ 6ivz
break; 6&'kN2
wXp:XZ:]T
QsxvA;7%
//count++; wmVb0~[
//if(count>4) Q[#8ErUY
// siteStop(); &d6ud|
} c\>I0HH;!
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{Mb<onW
System.err.println("文件下载结束！"); ng|^Zm%
} @8`I!fZ
catch(Exception e){e.printStackTrace ();} 3B%7SX
} o~y{9Q
W;R6+@I[
XNx$^I=
//获得文件长度 EUI*:JU-
public long getFileSize() Q\IViM
{ ;*zLf 9i
int nFileLength = -1; 5*A5Y E-
try{ ^1c7\"{
URL url = new URL(siteInfoBean.getSSiteURL()); RFS}!_t+|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aqk$4IG
httpConnection.setRequestProperty("User-Agent","NetFox"); Op9 ^Eu%n
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Hicd -'
int responseCode=httpConnection.getResponseCode(); ;Qq_
if(responseCode>=400) 6RxI9{ry
{ f^QC4hf0
processErrorCode(responseCode); x.t&NP^V)
return -2; //-2 represent access is error P}a$#a'!
} q$yg^:]2
#E=8kbD7
i" u|119
String sHeader; i Pr(X
VfJ{);
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for(int i=1;;i++) n2-+.9cY
{ ami>Pp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OW=3t#"7Kp
//Utility.log(in.readLine()); g8'8"9:xC
sHeader=httpConnection.getHeaderFieldKey(i); mh[,E8'd
if(sHeader!=null) `{K-eHlrM9
{ b@4UR<
if(sHeader.equals("Content-Length")) ):tv V
{ z]%@r 7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jia@HrLR
break; W\Scak>
} `Nvhp]E
} BcpbS%S
else GwDOxH'
break; KK>jV
} W!.FnM5x
} }oG6XI9
catch(IOException e){e.printStackTrace ();} iNi1+sm
catch(Exception e){e.printStackTrace ();} LzLJ6A>;R
]Z\W%'q+
_nzq(m1@
Utility.log(nFileLength); ,MJddbcg
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9'~qA(=.?
return nFileLength; 8/)q$zs
} Z>3~n
[ywF!#'){
Hr}"g@ <
//保存下载信息（文件指针位置） WhH60/`
private void write_nPos() 5"3`ss<m
{ I+kL;YdS
try{ 3l`"(5
output = new DataOutputStream(new FileOutputStream(tmpFile)); cy mC?8<
output.writeInt(nStartPos.length); .Xf_U.h$*@
for(int i=0;i<nStartPos.length;i++) "8zMe L
{ *UW 8|\;
// output.writeLong(nPos); BH^*K/^
output.writeLong(fileSplitterFetch.nStartPos); #k>n5cR@0
output.writeLong(fileSplitterFetch.nEndPos); rmvrv.$3
} {df;R|8l
output.close(); ?Q=(?yR0]
} X1oR
catch(IOException e){e.printStackTrace ();} s8]%L4lvu
catch(Exception e){e.printStackTrace ();} H@zv-{}T8
} (ESFR0
mP15PZ
$(0<T<\
//读取保存的下载信息（文件指针位置） n;xzjq-
private void read_nPos() rttKj{7E
{ [-Y~g%M
try{ ,mCf{V]#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _O87[F1
int nCount = input.readInt(); `hG`}G|^
nStartPos = new long[nCount]; rs>,p)
nEndPos = new long[nCount]; g]44|9x(W
for(int i=0;i<nStartPos.length;i++) BDPE.8s
{ pcscNUp
nStartPos = input.readLong(); r/NaoIrJV
nEndPos = input.readLong(); *1b0IQ$g
} ;XZN0A2
input.close(); B$JPE7h@[P
} 9%ct
catch(IOException e){e.printStackTrace ();} V?^qW#AG
catch(Exception e){e.printStackTrace ();} w > GW
} 3kGg;z6
Dvz 6 E
VY~*QF~P
private void processErrorCode(int nErrorCode) =|$U`~YB
{ suhnA(T{
System.err.println("Error Code : " + nErrorCode); .':17 $c`H
} c"`HKfL
RmKbnS$*q
~PF,[$?4n
//停止文件下载 Pk5\v0vkg
public void siteStop() >yVrIko
{ ^56D)A=
bStop = true; 3#udzC
for(int i=0;i<nStartPos.length;i++) V5h_uGOD
fileSplitterFetch.splitterStop(); e>!]_B1ad
5gx;Bp^_
*)\y52z
} 5$Kv%U
} .|L9}<
//负责部分文件的抓取 60>g{1]
**FileSplitterFetch.java #vy[v22
*/ &2@Rc?!6_P
package NetFox; ;Cx`RF w
~^Ga?Q_
>c:nr&yP
import java.io.*; F!C<^q~!
import java.net.*; Op9+5]XF
pG*W>F
'S v V10$5
public class FileSplitterFetch extends Thread { ,e`n2)
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String sURL; //File URL 5 8U[IGs(
long nStartPos; //File Snippet Start Position n~w[ajC/
long nEndPos; //File Snippet End Position D2MIV&pahP
int nThreadID; //Thread's ID 9ucoQ@
boolean bDownOver = false; //Downing is over $V<fJpA
boolean bStop = false; //Stop identical $'*{&/@
FileAccessI fileAccessI = null; //File Access interface _Eq,udCso
j9Z1=z
,FRa6;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XNvlx4
{ K;\fJ2ag
this.sURL = sURL; 1Nv qtVC
this.nStartPos = nStart; <Fl.W}?Q}
this.nEndPos = nEnd; B~<bc
nThreadID = id; rO1N@kd/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DYZk1
} gK *=T
5X]f}6kT
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public void run() VeFfkg4
{ V5jy,Qi)
while(nStartPos < nEndPos && !bStop) b|k(:b-G&.
{ pwVGe|h%,
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.k!2{A
try{ G [yI[7=d
URL url = new URL(sURL); ##] `
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1F2(MKOo!
httpConnection.setRequestProperty("User-Agent","NetFox"); 8k Sb92
String sProperty = "bytes="+nStartPos+"-"; v]q"{c/
httpConnection.setRequestProperty("RANGE",sProperty); d.U"lP/)D
Utility.log(sProperty); ? EhIK
6LT.ng
1yc$b+TH
InputStream input = httpConnection.getInputStream(); `[_p,,}Ir
//logResponseHead(httpConnection); NeewV=[%
v+d`J55
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byte[] b = new byte[1024]; .36]>8
int nRead; Ob|tA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xCu\jc)2
{ ~!Rf5QA85
nStartPos += fileAccessI.write(b,0,nRead); b|.<rV'BTt
//if(nThreadID == 1) B-$ps=G+z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }qhND-9#@
} OR10IS
"@xL9[d
G$lE0_j2{
Utility.log("Thread " + nThreadID + " is over!"); /EZ -
bDownOver = true; a{}8030S
//nPos = fileAccessI.write (b,0,nRead); BL\H@D
} p<RIvSqM
catch(Exception e){e.printStackTrace ();} BDi+*8
} 2d OUY $4
} TPi{c_ ]
j'SGZnsy*
4"+v:t)z6{
//打印回应的头信息 D<^K7tJui
public void logResponseHead(HttpURLConnection con) EuD$^#
{ #6 $WuIG
for(int i=1;;i++) 8/|1FI
{ 7z+Ngt' !
String header=con.getHeaderFieldKey(i); 4_ZHY?VRd
if(header!=null) T'14OU2N{Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (6)X Fp&
Utility.log(header+" : "+con.getHeaderField(header)); V67<Ky>
else pvM`j86 _
break; +'9xTd
} <ZoMKUuB
} ^%33&<mB}
}~ga86:n0
n=h!V$X
public void splitterStop() ^QTkre
{ zgSv -h+f
bStop = true; `S]DHxS
} B!1L W4^
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7}Jn`^!
} )5s-"o<
T FK#ign
HhUk9 >7
/* ^F+7@*u
**FileAccess.java Qy'-3GB
*//文件访问(定位，写) 0&6(y* #Z
package NetFox; )!l1
import java.io.*; iuoZk5O
KyzdJ^xC"
d((,R@N'
public class FileAccessI implements Serializable{ aw1f;&K4
kNUNh[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CN#2-[T
RandomAccessFile oSavedFile; T'%Rkag>
long nPos; k=.pcDX
6p~8(-nG
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public FileAccessI() throws IOException t[bZg9;
{ NKu*kL}W=
this("",0); X}]g;|~SN
} FzQ6UO~'
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9Ui|8e~=
public FileAccessI(String sName,long nPos) throws IOException .:TSdusr~
{ BHIC6i%
oSavedFile = new RandomAccessFile(sName,"rw"); m/1;os5+8
this.nPos = nPos; ,mD{4 >7
oSavedFile.seek(nPos); (fC U+
} !;&{Q^}
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5[rA>g~
public synchronized int write(byte[] b,int nStart,int nLen) qa/VSk!{
{ *>7Zc
int n = -1; 8FT@TUFb
try{ <Lfo5:.
oSavedFile.write(b,nStart,nLen); fzjZiBK@
n = nLen; [hKt4]R
} Znh)m
catch(IOException e) 0"xD>ue&
{ SQI =D8
e.printStackTrace (); {'q(a4
} -ob1_0
hkvymHaG
|6zx YuX
return n; ,gn**E
} ~5wT|d
@DCw(.k*
d?1[xv;
} 9 IY1"j0O
iVf8M$!m
9':MD0P/M
/* #~;:i
**SiteInfoBean.java ;Qdw$NuW
*/ Te&5IB-
package NetFox; ~#9(Q
*d,Z?S/
FKkL%:?
public class SiteInfoBean { ,Q>wcE6v
fdzaM&
1<&nHFJ;[
private String sSiteURL; //Site's URL t,R4q*
private String sFilePath; //Saved File's Path Q`[J3-Q*{
private String sFileName; //Saved File's Name Iq: G9M
private int nSplitter; //Count of Splited Downloading File iig@$ i#
kZHIzU
Nmu=p~f}3`
public SiteInfoBean() ,~qjL|9
{//nSplitter的缺省值为5 tJZ3P@ L
//default value of nSplitter is 5 g7<u eF
this("","","",5); #(Ezt% ^
} {&s.*5
?M@ff0
DeRC_ [
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -!pg1w06
{ 3`DwKv`+
sSiteURL= sURL; x_BnWFP
sFilePath = sPath; J+0T8 ?A
sFileName = sName; $ 2PpG|q
this.nSplitter = nSpiltter; !6DH6<HC
fs%l j_t
)w&k&TY4H
} R{SN.%{;
K._* ~-A
gqQ"'SRw
public String getSSiteURL() lc\f6J>HT
{ nM6/c
return sSiteURL; ;\)N7SJ
} )E(9 R(
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public void setSSiteURL(String value) h(3ko An
{ D;WQNlTU
sSiteURL = value; Q a8;MxK`
} Dro2R_j{
b;Uqyc
+C){&/=#
public String getSFilePath() ])uhm)U@
{ .]H1uoci|
return sFilePath; k<!xOg
} -@yu 9=DT
n>:|K0u"
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public void setSFilePath(String value) LKe~
{ t{RdqAF
sFilePath = value; =6LF_=}
} $g!~T!p=
oBZzMTPe
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public String getSFileName() -|nHwSrCZ/
{ a C<
return sFileName; oV Hh
} \?rBtD(
&WAJ;7f
%P tdFz$
public void setSFileName(String value) ]9/{
{ 15tT%TC
sFileName = value; $g+q;Y~i0
} ;Vh5nO
|}^BF%8V:
e:kd0)9
public int getNSplitter() w.6Gp;O
{ j9]H~:g$d
return nSplitter; 2P4$^G[
} tX *}l|;(
S,%BhQ[
=%+o4\N,
public void setNSplitter(int nCount) etkKVr;Kv
{ +1Ua`3dWN_
nSplitter = nCount; -P'KpX:]hd
} i#W0
} 'k(aZ"
XDcA&cM}p
EAi!"NJ
/* |#_`aT"
**Utility.java Eggdj+
*/ wEJ) h1=)^
package NetFox; /!L#cUog
!Al?B9KJ
?,0 5!]
public class Utility { An0Zg'o!G
?cdjQ@j~h
9XSZD93L
public Utility() +X&b
{ Zr U9oy&!C
?*h2:a$
i`)h~V|G
} ~i ImM|*0
g8^YDrH
//线程睡眠 qS{E+)P
public static void sleep(int nSecond) a2tRmil
{ :`w'}h7m
try{ lyYi2& %
Thread.sleep(nSecond); }E%#g#
} "UDV4<|^k
catch(Exception e) b ?-VZA:
{ Q4vl
e.printStackTrace (); FJl_2
} ollk {N
} sq~9 l|F
A:-r2;xB
//日志 quEP"
public static void log(String sMsg) G^Q8B^Lg
{ C_~hX G
System.err.println(sMsg); 8Q2qroT
} ':jsCeSB
@CJ`T&
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public static void log(int sMsg) G$)f5_]7{
{ >PBP:s1f4>
System.err.println(sMsg); eVy>
} $xl>YYEBMH
} +>uiI4g
C%l+<wpXO
S[zX@3eZV
/* wmQT$`$b
**TestMethod.java ~7}aW#
*/ eXdE?j
package NetFox; Z+G.v=2q<
y$7vJl.uS/
+4Uxq{.K
public class TestMethod { l9"T"9C{
8UahoNrSt
;I^+u0ga
public TestMethod() g*& |Eq/
{ ///xx/weblogic60b2_win.exe c'8pTP%[
try{ "7&DuF$s)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f1_b``M
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #OT8_D
SiteFileFetch fileFetch = new SiteFileFetch(bean); {r,MRZaa
fileFetch.start(); lPywrTG0
} [m9Iz!E
catch(Exception e){e.printStackTrace ();} %Ct^{k~1
nGqD{!i<
Z&VH7gi
} x]=s/+Y
7ZsBYP8%
k,mgiGrQ
public static void main(String[] args) 7i$)iNW
{ sOY+X
new TestMethod(); f0lpwwe
} |pA
} g$N/pg2>cT
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