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)); @j!(at4B
} 4fIjVx
for(int i=0;i<nEndPos.length-1;i++) ^TD%l8o6
{ )m#Y^
nEndPos = nStartPos[i+1]; ,k_"T.w
} BhYvEbt
nEndPos[nEndPos.length-1] = nFileLength; $%^](-
} Z($i+L%.
} {P_i5V?
\%&A? D
0 *;i]owV
//启动子线程 C1fd@6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b}DC|?~M
for(int i=0;i<nStartPos.length;i++) XG*> yra`
{ qyxd9Lk1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gy[anDE&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D>8p:^3g
nStartPos,nEndPos,i); `KtP;nG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); == E8^jYJw
fileSplitterFetch.start(); Xt:$H6 y
} lu00@~rx/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?=LT ^Zp`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $/lM %yXe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D;s%cL`
nEndPos = " + nFileLength); `#'j3,\6
// fileSplitterFetch[nPos.length-1].start(); pSbtm74
fgs@oaoZ
? )h8uf4
//等待子线程结束 Yn[>Y)
//int count = 0; c9G%;U)
//是否结束while循环 [-VK!9pQ
boolean breakWhile = false; $OG){'X
,oUzaEX
B~E">}=!
while(!bStop) @dk-+YxG
{ /{:XYeX
write_nPos(); %Z4*;VwQ
Utility.sleep(500); 7~FHn'xt
breakWhile = true; 4#}aLP
{:3\Ms#
HAL\j5i
for(int i=0;i<nStartPos.length;i++) &TY74w*
{ *RxJ8.G
if(!fileSplitterFetch.bDownOver) 1a/C(4_k
{ 2Mk;r*FT
breakWhile = false; }LCm_av
break; <T?-A}0uO
} 8^^ 1h
} z\oTuW*B
if(breakWhile) V'e%%&g~N
break; Q 8Hl7__^
PDPK|FU
@!=Ds'MJC
//count++; &ocuZ-5`
//if(count>4) JRi:MWR<r
// siteStop(); L{P'mG=4
} p:TE##
}ymW};W
Zj!,3{jX^
System.err.println("文件下载结束！"); p@kRo#~l
} >t.Lc.
catch(Exception e){e.printStackTrace ();} {?`7D:]`^
} =y-yHRC7
*~g*J^R}
1&! i:F#
//获得文件长度 "D8WdV(
public long getFileSize() ~CT]&({
{ >G8I X^*sG
int nFileLength = -1; &:5*^1oP
try{ L'r&'y[
URL url = new URL(siteInfoBean.getSSiteURL()); z?<B@\~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lHtywZ@%3
httpConnection.setRequestProperty("User-Agent","NetFox"); rbnAC*y8'L
,+ G
Gn=b_!
int responseCode=httpConnection.getResponseCode(); '=vZAV`
if(responseCode>=400) ?5J# yn
{ #lrwKHZ+
processErrorCode(responseCode); X+ITW#
return -2; //-2 represent access is error 'bJGQ[c
} Bkd$'7UT
w") G:K
)-_^vB
String sHeader; ~;3#MAG
BW7AjtxQ&
A!Cby!,
for(int i=1;;i++) !Pw*p*z
{ |J,zU6t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aSvv(iV
//Utility.log(in.readLine()); . 2$J-<O
sHeader=httpConnection.getHeaderFieldKey(i); 5PO_qr=Hx
if(sHeader!=null) JyZuj>` 6
{ *0xL(
if(sHeader.equals("Content-Length")) Vt(Wy
{ q@~g.AMCB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'KA$^
break; 4?1Qe\A^
} '";#v.!
} f~T7?D0u}N
else V.&F%(L
break; e?.j8Q~
} X#ttDB
} 9 Gd6/2
catch(IOException e){e.printStackTrace ();} >lV,K1Z
catch(Exception e){e.printStackTrace ();} salC4z3
+#MXeUX"
O3@DU#N&s
Utility.log(nFileLength); uVUU1@
vSR&>Q%X
;:D-}t;
return nFileLength; 4`Ud\Jm[s
} ?OFa Q
3/`BK{
6 X~><r
//保存下载信息（文件指针位置） ).;{'8Q
private void write_nPos() i"}z9Ae~.
{ ]0."{^ksL
try{ uK@d?u!`
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ob/)f)!!
output.writeInt(nStartPos.length); y017 B<Ou
for(int i=0;i<nStartPos.length;i++) 6?F88;L
{ 4>=M"DhB
// output.writeLong(nPos); _ l|%~
output.writeLong(fileSplitterFetch.nStartPos); ~D9Cu>d9
output.writeLong(fileSplitterFetch.nEndPos); 7A\`
} o6MFMA+vi
output.close(); d}4NL:=&
} :awkhx
catch(IOException e){e.printStackTrace ();} OP1`!P y
catch(Exception e){e.printStackTrace ();} ^$:w
} qR'FbI
!b+4[xky
Zu.hcDw1
//读取保存的下载信息（文件指针位置） ,!l_
private void read_nPos() :|s8v2am
{ zG#5lzIu,
try{ F,Q;sq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oRCc8&
int nCount = input.readInt(); 'nq=xi@RC
nStartPos = new long[nCount]; Y${'
nEndPos = new long[nCount]; {!|4JquE_
for(int i=0;i<nStartPos.length;i++) $XhMI;h
{ 8X,6U_>#a
nStartPos = input.readLong(); ~pRgTXbz
nEndPos = input.readLong(); $(9QnH1KY
} .2fvRN92
input.close(); 7<xnE]jdq
} A4tk</A
catch(IOException e){e.printStackTrace ();} pX_#Y)5
catch(Exception e){e.printStackTrace ();} @wcF#?J
} ^xa, r#N:V
@q'kKVJs
&IQ=M.!r
private void processErrorCode(int nErrorCode) uI-T]N:W8x
{ P+j=]Yg
System.err.println("Error Code : " + nErrorCode); 9~Dg<wQ
} z?\it(
KQPu9f9
lAU99(GXV
//停止文件下载 .rtA sbp.!
public void siteStop() *SNdU^!
{ (zo7h
bStop = true; i=EOk}R
for(int i=0;i<nStartPos.length;i++) _Q5mPBO
fileSplitterFetch.splitterStop(); 1(o\GI3:
LDjtkD.r
zl1*GVg
} Xfc$M(a K{
} m;dwt1'Zw
//负责部分文件的抓取 >R F|Q
**FileSplitterFetch.java XZIapT
*/ '|IcL1c=I
package NetFox; (!nkv^]
yNns6
(t-hi8"
import java.io.*; 5tlRrf
import java.net.*; 1tNL)x"w
iqDyE*a
"0CFvN'4
public class FileSplitterFetch extends Thread { =npE?wK
L0g+RohW
?),b902C
String sURL; //File URL [e+Y7M7
long nStartPos; //File Snippet Start Position 7_\sx7h{3
long nEndPos; //File Snippet End Position Pp_4B
int nThreadID; //Thread's ID A"JdG%t>.h
boolean bDownOver = false; //Downing is over eg;7BZim{
boolean bStop = false; //Stop identical EwPrh
FileAccessI fileAccessI = null; //File Access interface !J7`frv"(
L)JB^cxf
y*iZ;Bv j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LIID(s!bX
{ ~71U s
this.sURL = sURL; ;JkSZs3
this.nStartPos = nStart; Ce}`z L
this.nEndPos = nEnd; 8Rj5~+5
nThreadID = id; ^@^8iZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;\RVC7
} c[Fc3
_KH91$iW8m
,R{&x7
public void run() 60+zoL'
{ 6^b)Q(Edut
while(nStartPos < nEndPos && !bStop) 64/ZfXD
{ *O_fw 0jV
\L*%?~
_w\9 \<%
try{ 6eSo.@*l
URL url = new URL(sURL); CQWXLQED>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DsHF9Mn
httpConnection.setRequestProperty("User-Agent","NetFox"); D]@(LbMG4
String sProperty = "bytes="+nStartPos+"-"; b9j}QK
httpConnection.setRequestProperty("RANGE",sProperty); '##?PQ*u
Utility.log(sProperty); A^OwT#
c]9gf\WW
mo| D
InputStream input = httpConnection.getInputStream(); 5T;LWS
//logResponseHead(httpConnection); ahl|N`
rRe5Q
f-F=!^.
byte[] b = new byte[1024]; +VUkV-kP
int nRead; {lds?AuK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V8n {k'
{ ,XT,t[w
nStartPos += fileAccessI.write(b,0,nRead); X?_rD'3
//if(nThreadID == 1) WzzA:X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \ja6g
} UXct+l
.\XRkr'-
tyR?A>F4
Utility.log("Thread " + nThreadID + " is over!"); Ub3$`
bDownOver = true; KtQs uL%
//nPos = fileAccessI.write (b,0,nRead); IO\1nB$0nb
} KTm^}')C8
catch(Exception e){e.printStackTrace ();} Cv,WG]E7(
} >eGg 1
} ` i[26Qb
1TZ[i
zb0NqIN:
//打印回应的头信息 u2#q7}
public void logResponseHead(HttpURLConnection con) ud/!@WG
{ v<1@"9EH
for(int i=1;;i++) 84(Jo_9
{ .V;,6Vq
String header=con.getHeaderFieldKey(i); HkD.W6A3
if(header!=null) MRpMmu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); + f6LG 0q
Utility.log(header+" : "+con.getHeaderField(header)); d'_q9uf'
else $wM..ee
break; pz^S3fy
} 1clzDwW
} \n_7+[=E
='"Yj
L0![SE>
public void splitterStop() [Hx}#Kds
{ !RKuEg4hQ
bStop = true; H1-DK+Q:
} 2U./ Yfk\
=zn'0g,J4
dy6zrgxygP
} 2? E;(]dQ
1|sem(t
n{QyqI
/* ^(;x-d3
**FileAccess.java oCCtjr
*//文件访问(定位，写) ROkwjw
package NetFox; qJ;~ANwt
import java.io.*; .<t{saToU
)>ff"| X
5RLO}Vn]
public class FileAccessI implements Serializable{ 29:2Xu i
sPK]:iC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1sXCu|\q
RandomAccessFile oSavedFile; "==c
long nPos; "W5MZ
hE:~~ox
O<vBuD2
public FileAccessI() throws IOException 9':Ipf&x
{ G!FdTvx$
this("",0); n~lB}
} _h1bVd-
9'(_*KSH
}d5]N
public FileAccessI(String sName,long nPos) throws IOException 0eO!,/
{ $PMr)U
oSavedFile = new RandomAccessFile(sName,"rw"); >9w^C1"
this.nPos = nPos; 0s`6d;
oSavedFile.seek(nPos); o*$KiD
} F.TIdkvp
Jz''UJY/O
7T[L5-g
public synchronized int write(byte[] b,int nStart,int nLen) OXLB{|hH80
{ 2]fTDKh
int n = -1; tM5(&cQ!d
try{ z 4}"oQk:r
oSavedFile.write(b,nStart,nLen); *$7^.eHfdd
n = nLen; %ZRv+}z
} Z*Ffdh>*:&
catch(IOException e) G:e=9qTf
{ yl>^QMmo
e.printStackTrace (); -, +o*BP
} Yh]a4l0
bAt!S
ta&z lZt
return n; hEjvtfM9\-
} "0!#De
6ud?US(
D?ic~-&
} z\v
I6WHC*
;FlDRDZ%
/* @IL@|Srs8
**SiteInfoBean.java y6am(ugE
*/ Q8HNST($?
package NetFox; @yGnrfr
!o| ex+z;
f.ua,,P.
public class SiteInfoBean { -~.+3rcZ]
tic3a1
j&[lDlI_
private String sSiteURL; //Site's URL UVXruH
private String sFilePath; //Saved File's Path e[k\VYj[
private String sFileName; //Saved File's Name Fz8& Jn!
private int nSplitter; //Count of Splited Downloading File WA}'[h
%w_MRC
!T`g\za/
public SiteInfoBean() =0e>'Iw2
{//nSplitter的缺省值为5 ?o V.SG'
//default value of nSplitter is 5 fe4/[S{a
this("","","",5); OY"BaSEOw}
} 1mgw0QO
^/2O_C
[GyPwb-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]@SEOc@ j
{ (6[<+j&.
sSiteURL= sURL; 2;:]Q.g
sFilePath = sPath; uYTyR;a
sFileName = sName; =2Ju)!%wr
this.nSplitter = nSpiltter; -X EK[
34k(:]56|
:qXREF@h
} f[zKA{R
,9|7{j|u
v'L"sgW6I
public String getSSiteURL() !h&h;m/c
{ 1|*%
return sSiteURL; t":^:i'M
} [9EL[}
#~*v*F~3
=]Y'xzJuu
public void setSSiteURL(String value) D{]w+
{ 'o]}vyz;
sSiteURL = value; l7ES*==&@0
} cmf*BkS
O,@QGUoA
F[ ^ p~u{
public String getSFilePath() ,vi6<C\
{ (4l M3clF
return sFilePath; 9Lt3^MKa"
} YbVZK4
a6T!)g
;XY#Jl>tg
public void setSFilePath(String value) I<lkociUCG
{ #r&yH^-
sFilePath = value; \XY2s&"
} MMRO@MdfV
i+-Y"vRi
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public String getSFileName() 1g!%ej jd
{ 1\f8-:C
return sFileName; .:['&; k
} eF8um$t9
bB.nevb9p
G* mLb1
public void setSFileName(String value) o,1Fzdh6(
{ uN9.U _
sFileName = value; arPqVMVr
} IOUzj{G#
K!jau|FS
+/*A}!#v
public int getNSplitter() '\7&Iz:%
{ +Y~,1ai 5^
return nSplitter; 'vIVsv<p
} T7G{)wm
6l?KX
]=^NTm,
public void setNSplitter(int nCount) z81`Lhg6
{ %cc<>Hi
nSplitter = nCount; wd:SBU~f5*
} vP<8,XG
} \]/6>yT
$_Lcw"xO
\4q1<j
/* e3&.RrA
**Utility.java ZONe}tv:
*/ VN4H+9E
package NetFox; & V/t0
vw q Y;7
5|[\Se#
public class Utility { BYDOTy/%nJ
oX]c$<w5
X15e~;&
public Utility() u|8V7*)3
{ V,9UOC,Gn
BI)$aR
ErMA$UkJ
} My>{;n=}
W^nG\"T^
//线程睡眠 0Z[8d0
public static void sleep(int nSecond) ;(Qm<JAa
{ 0j~C6vp
try{ _EZrZB
Thread.sleep(nSecond); V@>s]]HMq#
} `Axn
catch(Exception e) ab5z&7Re6
{ {wfe!f
e.printStackTrace (); [.iz<Yh
} oxm3R8S
} hz+x)M`Y
OGO4~Up
//日志 ?Da!QH >,]
public static void log(String sMsg) 8BJ&"y8H
{ 3m`y?Dd
System.err.println(sMsg); l7JY`x
} V-iY2YiR
|4FvPR[
*FUbKr0
public static void log(int sMsg) j1,ir
{ V5LzUg]
System.err.println(sMsg); Vz&!N/0i
} ygp NMq#?X
} NvfQa6?;
0l ]K%5#
Y;XEC;PXD
/* S(*SUH
**TestMethod.java O%kX=6
*/ Xn3Ph!\Z5e
package NetFox; gg%OOvaj5
O}#h^AU-BS
] Vbv64M3
public class TestMethod { F.JvMy3
O9W|&LAL
"h}miVArS
public TestMethod() }%9A+w}o
{ ///xx/weblogic60b2_win.exe Lm}:`
try{ RI_3X5.KQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =sW(2Im
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e'z[JG=
SiteFileFetch fileFetch = new SiteFileFetch(bean); wg=ge]E5
fileFetch.start(); e[7n`ka '
} T/&4lJ^2l^
catch(Exception e){e.printStackTrace ();} {aWTT&-N
q>*+.~
]MP6VT
} @ zE>n
x;Jy-hMNl
xV4 #_1(
public static void main(String[] args) _ZfJfd~
{ y++[:M
new TestMethod(); auTApYS53
} Z;QbqMj
} i7f/r.
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