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)); g*b%
} T5-50nU,~
for(int i=0;i<nEndPos.length-1;i++) C z4"[C`;
{ EfcoJgX
nEndPos = nStartPos[i+1]; IJs*zzR
} PsEm(.z
nEndPos[nEndPos.length-1] = nFileLength; !0fpD'f!n
} cA`R~o"
} WA8Qt\Q
(".`#909
/+"BU-aQk
//启动子线程 HpSgGhL'J&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]b.@i&M
for(int i=0;i<nStartPos.length;i++) IpoZ6DB$
{ |Ag~k? QC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7sC$hm]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O=MO M
nStartPos,nEndPos,i); be$wGO=Ts
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >VE,/?71@
fileSplitterFetch.start(); L<J';#BD
} ]H[RY&GY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zu_m$Mx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Dvo.yn|kB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P_z3TK
nEndPos = " + nFileLength); 1V+a;-?
// fileSplitterFetch[nPos.length-1].start(); v~?d7p{
z\oq b)a
tcwE.>5O
//等待子线程结束 %^p1ax
//int count = 0; 9|D!&=8
//是否结束while循环 n9050&_S
boolean breakWhile = false; }7IS:"tu
j7xoe9;TxI
H"WkyvqXb
while(!bStop) 82YTd(yB
{ /$! /F@^
write_nPos(); 6sRn_y
Utility.sleep(500); 0J7[n*~
breakWhile = true; .2C}8GGC'
Fm`hFBKW
+%7yJmMw
for(int i=0;i<nStartPos.length;i++) pOyM/L
{ a"b9h{h@
if(!fileSplitterFetch.bDownOver) ot;j6eAH~E
{ F6}Pwz[c
breakWhile = false; DFwkd/3"
break; ,1Suq\ L
} c;&m}ImLe.
} q<@f3[A
if(breakWhile) \"V7O'S)&
break; G+=euK2]
kmi[u8iXD_
?#<Fxme
//count++; w_ kHy_)
//if(count>4) IwZn%>1N
// siteStop(); {e/12q
} n (C*LK
]-bA{@tP.
k*J}/HO
System.err.println("文件下载结束！"); >e/;
} Cj _Q9/
catch(Exception e){e.printStackTrace ();} N~;=*)_VH
} ua0`&,a3I
WQ\'z?P
- A x$Y
//获得文件长度 SJ6lI66OX
public long getFileSize() U8c0N<j
{ _.' j'j%
int nFileLength = -1; ?uc=(J+6
try{ hvtg_w6K
URL url = new URL(siteInfoBean.getSSiteURL()); 6|V713\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1/jJ;}
httpConnection.setRequestProperty("User-Agent","NetFox"); eZ[CqUJ&
^cZF#%k
9jDV]!N4
int responseCode=httpConnection.getResponseCode(); +6B(LPxgP
if(responseCode>=400) 6^H64jM
{ 2IFri|;-eb
processErrorCode(responseCode); ^'lx5+-
return -2; //-2 represent access is error Dq)V] Zx
} UAFl+d!
*Y?rls`
<T)9mJYr
String sHeader; WB'&W=
-m(9*b{h@
O"<D0xzF?
for(int i=1;;i++) 0vbn!<:
{ $z1u>{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7m~+HM\
//Utility.log(in.readLine()); Uq<c+4)5
sHeader=httpConnection.getHeaderFieldKey(i); (x@|6Sb
if(sHeader!=null) o|>2X[T
{ \L}Soe'
if(sHeader.equals("Content-Length")) f>s3Q\+
{ 2oXsPrtZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *TfXMN?w
break; r,(rWptf4
} $iUK, ?
} rZLTai}`>
else Y/2@PzA|
break; +XLy Pj
} KqG:o+V=
} J/>Y mi,
catch(IOException e){e.printStackTrace ();} b/:9^&z
catch(Exception e){e.printStackTrace ();} #Q.A)5_
"EQ`Q=8
cgNK67"(
Utility.log(nFileLength); -K0>^2hh
/csj(8^w
c/DB"_}!a
return nFileLength; 0.'$U}#b
} 1.+0=M[h
`Xc~'zG
TppR \[4]
//保存下载信息（文件指针位置） {" woBOaA
private void write_nPos() (n;#Z,
{ =H%c/Jty
try{ g,h'K
output = new DataOutputStream(new FileOutputStream(tmpFile)); -Ob'/d5&
output.writeInt(nStartPos.length); i^eU!^KF
for(int i=0;i<nStartPos.length;i++) z|^:1ov,
{ 3,DUT{2
// output.writeLong(nPos); \HF|&@}hU
output.writeLong(fileSplitterFetch.nStartPos); w!,~#hbt6
output.writeLong(fileSplitterFetch.nEndPos); }b)7gd=
} vOy;=0$
output.close(); 2a'b}<|[(
} ekND>Qjj
catch(IOException e){e.printStackTrace ();} 8iaP(*J
catch(Exception e){e.printStackTrace ();} y!&6"l$K]
} .aV#W@iyK
qF C0$:z&
.|^L\L(!
//读取保存的下载信息（文件指针位置） 1v)ur\>R
private void read_nPos() m^Qc9s#D
{ \2KwF}[m
try{ 48vKUAzx`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I(y:Td
int nCount = input.readInt(); 4/vQ/>c2j
nStartPos = new long[nCount]; V]dzKNFi
nEndPos = new long[nCount]; lK;|ciq"c7
for(int i=0;i<nStartPos.length;i++) ?9'Ukw` g
{ Xb6X'rY
nStartPos = input.readLong(); L}5nq@Uu)
nEndPos = input.readLong(); .xo#rt9_"=
} i}"Eu< P
input.close(); EVZuwbO)|
} &o%IKB@
catch(IOException e){e.printStackTrace ();} 2L Kpwz?
catch(Exception e){e.printStackTrace ();} L}NckL
} 5V5Nx(31i
.`*h2
Y` t-Bg!~
private void processErrorCode(int nErrorCode) Teh _
{ 04g=bJ
System.err.println("Error Code : " + nErrorCode); +AkAMZ"Mg
} q;a"M7
$L%gQkz_
t1"-3afe
//停止文件下载 xo3bY6<n
public void siteStop() V_+XZ+7Lx}
{ }GI8p* ]o=
bStop = true; *{[jO&&J
for(int i=0;i<nStartPos.length;i++) t)o!OEnE
fileSplitterFetch.splitterStop(); KnK8\p88\
kEiWE|
uflRW+-2
} Mtxn@m{i;"
} }8tD|t[
//负责部分文件的抓取 a^/j&9
**FileSplitterFetch.java 4+46z|
*/ 1~rZka[s
package NetFox; s\&qvL1D
}\Kki
ukNB#2"
import java.io.*; .rpKSf.
import java.net.*; |uL"/cMW7
6WUP#c@{
L-SWs8
public class FileSplitterFetch extends Thread { ,xmL[Yk,
6j uNn}
#$k6OlK-r"
String sURL; //File URL xg*)o*?
long nStartPos; //File Snippet Start Position S 2vjjS
long nEndPos; //File Snippet End Position %z1y3I|`[t
int nThreadID; //Thread's ID $;~
boolean bDownOver = false; //Downing is over %49^S&
boolean bStop = false; //Stop identical ))Q3;mI"
FileAccessI fileAccessI = null; //File Access interface K`%{(^}.
~Psv[b=]
uRIa Nwohv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a(cZ]`s]*
{ JSO'. [N
this.sURL = sURL; w K)/m`{g
this.nStartPos = nStart; o m9zb&{tu
this.nEndPos = nEnd; +2Xq+P
nThreadID = id; wP-BaB$_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y243mq-
} i_<Uk8
R/5@*mv{
j\SvfZ0"
public void run() Y9^;TQ+#
{ ;F3#AO4(
while(nStartPos < nEndPos && !bStop) |,ws3
{ yex4A)n9"'
_pZ2^OO@
gxa@da
try{ cow]qe6K
URL url = new URL(sURL); iLhxcM2K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ftr?@^
httpConnection.setRequestProperty("User-Agent","NetFox"); +2&+Gh.h
String sProperty = "bytes="+nStartPos+"-"; +,wCV2>\3
httpConnection.setRequestProperty("RANGE",sProperty); [*i6?5}-
Utility.log(sProperty); znVao %b
Fkq;Q
LS(J%\hMDm
InputStream input = httpConnection.getInputStream(); 6KpG,%2L#
//logResponseHead(httpConnection); b`%(.&
22`N(_
.|d2s
byte[] b = new byte[1024]; H<YhO&D*u
int nRead; Ic!8$NhRS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L"Vi:zdp
{ f3bZ*G%f
nStartPos += fileAccessI.write(b,0,nRead); B`I9
//if(nThreadID == 1) fG{ 9doUD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d]bM,`K* 6
} H6fR6Kr4j
XMJEIG
(j*1sk
Utility.log("Thread " + nThreadID + " is over!"); J|Af`HJ
bDownOver = true; .WeP]dX%:f
//nPos = fileAccessI.write (b,0,nRead); xWhi>
} }iu(-{Z
catch(Exception e){e.printStackTrace ();} ;8VvpO^G/
} 3B+ F'k&#
} =5zx]N1r
BkO)hze
+[2X@J
//打印回应的头信息 Po+tk5}''5
public void logResponseHead(HttpURLConnection con) h~F`[G/'
{ !"dn!X
for(int i=1;;i++) ~wX4j
{ ]t'bd<O
String header=con.getHeaderFieldKey(i); xQKD1#y
if(header!=null) ab5uZ0@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pN]$|#%q(
Utility.log(header+" : "+con.getHeaderField(header)); [>pqf
else Y64B"J=P9
break; "-tTN
} *,Mg
} x>E**a?!L
6Eu&%`
m{ya%F
public void splitterStop() ^Z9v_qB
{ =z]8;<=pL
bStop = true; JW`Kh*,~<
} ~w>Z !RuhT
]0g%)fuMf
|H(Mmqgk
} [;]@PKW?w
JN{xh0*
_tGR:E
/* e1k\:]6
**FileAccess.java cuw3}4m%
*//文件访问(定位，写) 8/4Gr8o
package NetFox; wG&+*,}
import java.io.*; HOb-q|w
H=7zd|W
[xVE0l*\
public class FileAccessI implements Serializable{ ;7F|g
H$ sNp\[{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .W>8bg'u9
RandomAccessFile oSavedFile; 7%(|)3"V
long nPos; B-OuBS,fwC
T21SuM
0H V-e
public FileAccessI() throws IOException j&S8x|5
{ 4't@i1Ll(
this("",0); yL&_>cV
} u D.E>.B
kS>'6xXH
~'4:{xH
public FileAccessI(String sName,long nPos) throws IOException R.g'&_zx
{ kRk=8^."By
oSavedFile = new RandomAccessFile(sName,"rw"); zn4Yo
this.nPos = nPos; t?-7Z6
oSavedFile.seek(nPos); j=^b'dyL
} J6!t"eB+
;,z^!bD
g>[|/z P
public synchronized int write(byte[] b,int nStart,int nLen) W biUz2)
{ UeRx ^
int n = -1; Xcq9*!%o
try{ kUJ\AK
oSavedFile.write(b,nStart,nLen); GQ-owH]
n = nLen; #0-!P+c[
} JuGQS24
catch(IOException e) *5i~N}
{ EO|r
e.printStackTrace (); ))n7.pB9/
} o(W|BD!
mne^PSI:
%qzpt{'?<
return n; u+]v.Mt
} |wf:|%
zS:89y<
F:/R'0
} 5JbPB!5;
?80@+y]
+ R)x5
/* uP/WRQ{rW>
**SiteInfoBean.java ? OBe!NDf
*/ ^i{B8]2,
package NetFox; %*.;3;m
^g,[#Rh
cU25]V^{\
public class SiteInfoBean { 5 TD"
lLHHuQpuj
xG_ ;F
private String sSiteURL; //Site's URL {rWu`QT
private String sFilePath; //Saved File's Path N0c+V["s
private String sFileName; //Saved File's Name `8F%bc54iw
private int nSplitter; //Count of Splited Downloading File ZkYc9!anY
>GiM?*cC
?6
public SiteInfoBean() #K7i<Bf
{//nSplitter的缺省值为5 !MB%
//default value of nSplitter is 5 &7 }!U
this("","","",5); OwP9=9};
} L%a ni}V
tg~&kaz
66=6;77
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E{r_CR+8
{ ,_T,B'a:
sSiteURL= sURL; [;VNuF
sFilePath = sPath; _Z6/r^c
sFileName = sName; r0kA47
this.nSplitter = nSpiltter; J+&AtGq]u
J p .wg
CF^7 {g(y_
} -8tWc]c |4
zQ {g~x
GI$t8{M
public String getSSiteURL() ',0~\V
{ vjJ!d#8
return sSiteURL; Cc]s94
} ~}4o=O(
^h^2='p
+byw*Kk
public void setSSiteURL(String value) !23W=N}82
{ }i/&m&VU
sSiteURL = value; F|V_iC+
} +D4Nu+~BSN
w\_NrsO!x
0|{U"\
public String getSFilePath() ]t1)8v2w>
{ N|Ua|^
return sFilePath; ##u+[ !
} q yy.3-(
7F`QN18>(
7&klX
public void setSFilePath(String value) )+ Wr- Yay
{ 1l\O9D +$
sFilePath = value; nl5K1!1
} yQhrPw> m
a-Cp"pKlVY
PZpwi?N
public String getSFileName() ~>D;2 S(a
{ d"XS;;l%<
return sFileName; 5]; 8
} ;k7` `
]Vl5v5_
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public void setSFileName(String value) {<~XwJ.
{ z.Y7u3K.8
sFileName = value; HcHfwLin0
} %8$JL=c
^i-%FY_i5}
\9se~tAl3
public int getNSplitter() jXi<ZJ
{ -5vc0"?E
return nSplitter; o^&; `XOd
} N,'JQch},8
(L|SE4
[X^JV/R
public void setNSplitter(int nCount) v.6"<nT2
{ =]xNpX)
nSplitter = nCount; .1I];Cy0D
} r'&9'rir2
} 9aZ3W<N`M
kc8GnKM&mc
>Fx$Rty
/* h#]}J}si
**Utility.java /gy;~eB01
*/ (:+IS W
package NetFox; h,140pW
4C01=,6ye
-ZQ3^'f:0J
public class Utility { @aCg1Rm
)r?i^D&4
\U !<-
public Utility() 4N$svA
{ a2=wJhk
Y[s
-&,NM
} x0lX6 |D
;%dkwKO
//线程睡眠 i'e^[oZ
public static void sleep(int nSecond) Vg \-^$
{ QwT]| 6>
try{ qZ\zsOnp
Thread.sleep(nSecond); ~d5"<`<^o
} _\]D<\St
catch(Exception e) z(\H.P#
{ oSa FmP
e.printStackTrace (); 34;c00
} CdaB.xk
} >D:S)"
6{7O
//日志 XIjSwR kYJ
public static void log(String sMsg) 3:Z(tM&-O
{ m]"YR_
System.err.println(sMsg); 3lL:vD5(
} B.P64"w
"BFW&<1
'|XP}V0I
public static void log(int sMsg) X2@o"xU
{ $}KYpSV
System.err.println(sMsg); @{CpC
} :>3&"T.
} U1q$B32
+:'Po.{"
zi-+@9T
/* TS[Z<m
**TestMethod.java b$$XriD]
*/ wd#AA#J;*
package NetFox; yPQ{tS*t
+'n1?^U
/pk;E$qv
public class TestMethod { e0$mu?wd-
(QRl -| +
l&|{uk
public TestMethod() NXmj<azED
{ ///xx/weblogic60b2_win.exe teB{GR
try{ _b5iR<f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WX=+\`NyJ(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kcOpO<oE
SiteFileFetch fileFetch = new SiteFileFetch(bean); @B^'W'&C
fileFetch.start(); ]yIy~V
} <.v6w*+{/
catch(Exception e){e.printStackTrace ();} n9J>yud|
[KE4wz+s{
BuvBSLC~
} B0KM~cCPQP
g8x8u|
\)#3S $L~
public static void main(String[] args) Q`s(T
{ * ;M?R?+
new TestMethod(); )xK!i.
} b,`\"'1
} nWl0R=
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