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)); W #kOcw
} R<n'v.~"A
for(int i=0;i<nEndPos.length-1;i++) xF8^#J6>
{ 0'0GAh2
nEndPos = nStartPos[i+1]; I7q}<"`
} tjTnFP/=
nEndPos[nEndPos.length-1] = nFileLength; pw5uH
} %ryYa
} YRm6~c
E1-BB
y)e8pPDG
//启动子线程 ]3iQpL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i917d@r(<
for(int i=0;i<nStartPos.length;i++) zBTyRL l
{ I[v6Y^{q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %^CoWbU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -'mTSJ.}
nStartPos,nEndPos,i); I8:A]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yvp$s
fileSplitterFetch.start(); U sS"WflB
} ~y.t amNW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >Kjl>bq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TcM;6h`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zLda&#+
nEndPos = " + nFileLength); +=N#6#1
// fileSplitterFetch[nPos.length-1].start(); "MNI_C#{
<@z!kl
HXp$\%A)
//等待子线程结束 txp^3dZ`^
//int count = 0; (6#, $Ze
//是否结束while循环 YZyV
boolean breakWhile = false; -\V!f6Q
,`O.0e4pn
QpZCU]
while(!bStop) $)6%LG_@
{ Hlj_oDL
write_nPos(); lOuO~`,J
Utility.sleep(500); E+!A0!1
breakWhile = true; A,;V|jv9
M4`.[P4
+#V.6i
for(int i=0;i<nStartPos.length;i++) nA?Ks!9T
{ z[~ph/^
if(!fileSplitterFetch.bDownOver) gJC~$/2
{ vlS+UFH0
breakWhile = false; 3BzC'nplm
break; vle`#c.
} b>Em~NMu_
} /_l$h_{DH
if(breakWhile) o!-kwtw`l
break; cA8A^Iv:0
6A23H7
C_ 4(-OWq
//count++; JULns#tx}
//if(count>4) y8arFG
// siteStop(); y1c2(K>tu
} M!)~h<YL
#M~6A^)
a*(,ydF|L
System.err.println("文件下载结束！"); l}MVk%[
} yJn<S@)VT:
catch(Exception e){e.printStackTrace ();} lzDA0MPI:
} '`nf7b(
VY|'7in"M
,\Uc/wR
//获得文件长度 ziTE*rNJ
public long getFileSize() [.j&~\AG
{ x=%wPVJ
int nFileLength = -1; tEFbL~n
try{ b[s=FH]#N
URL url = new URL(siteInfoBean.getSSiteURL()); L }L"BY3$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J,Rp&tavt:
httpConnection.setRequestProperty("User-Agent","NetFox"); <A`zK
Mj5&vs~n;
;:A/WU.^
int responseCode=httpConnection.getResponseCode(); 3s B9t X
if(responseCode>=400) VSLi{=#
{ k|D =Q
processErrorCode(responseCode); &~{0@/
return -2; //-2 represent access is error I:Q3r"1
} yYN_]&ag
fuao*L]
}LTyXo
String sHeader; GMW,+
/|#";QsPN
6TkV+\
for(int i=1;;i++) &X&msEM
{ ;U<}2M!g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cl1>S3
//Utility.log(in.readLine()); TKs l.|
sHeader=httpConnection.getHeaderFieldKey(i); bJ5 VlK67R
if(sHeader!=null) GX0S9s
{ u#Y#,:{
if(sHeader.equals("Content-Length")) dk>qTY+j5
{ `),ACkU>U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _oAWj]~rO
break; %D6HY^]ayw
} E@[ZwTnJ
} wGhy"1g#
else L)yc_ d5
break; @tzL4hy%^j
} ={[9kR i
} Ce`#J6lT
catch(IOException e){e.printStackTrace ();} #Pr w2u
catch(Exception e){e.printStackTrace ();} V<ExR@|}.%
Gk-49|qIV
VbfTdRD-
Utility.log(nFileLength); hA:RVeS{
O0RV>Ml'&
2qpUUo f
return nFileLength; M T]2n{e
} 4D=^24f`0
`PS^o#
v4Mn@e_#c
//保存下载信息（文件指针位置） aaRc?b'/
private void write_nPos() C7Ny-rj}IA
{ Gph:'3 *X
try{ #fT<]j(
output = new DataOutputStream(new FileOutputStream(tmpFile)); zTS P8Q7
output.writeInt(nStartPos.length); hmp!|Q[)
for(int i=0;i<nStartPos.length;i++) oxZXY]$y
{ XpIl-o&re
// output.writeLong(nPos); (,^jgv|I
output.writeLong(fileSplitterFetch.nStartPos); 0'zX6%
output.writeLong(fileSplitterFetch.nEndPos); hF`Qs
} witx_r
output.close(); P&sYS<9q
} ^t}8E2mq
catch(IOException e){e.printStackTrace ();} lcfX(~/m^
catch(Exception e){e.printStackTrace ();} " 3tk"#.#
} (8Q*NZ
I4(z'C
cH6<'W{*
//读取保存的下载信息（文件指针位置） =O??W8u
private void read_nPos() "Ta"5XW
{ bwyj[:6l
try{ lN~u='Kc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z$Z{ LR
int nCount = input.readInt(); \'.|7{Xu
nStartPos = new long[nCount]; s6(bTO.
nEndPos = new long[nCount]; `G "&IQ8.
for(int i=0;i<nStartPos.length;i++) 7u<C&Z/
{ wu~?P`
nStartPos = input.readLong(); LXS)(-&
nEndPos = input.readLong(); T7LO}(I.&
} {66P-4Ev(
input.close(); Ft<B[bQ
} ycj\5+g
catch(IOException e){e.printStackTrace ();} ^SWV!rrg
catch(Exception e){e.printStackTrace ();} +j(7.6ia
} w)Z-, J
kK_9I (7c
=-E%vnU
private void processErrorCode(int nErrorCode) jX&/ e'B
{ 9a$ 7$4m
System.err.println("Error Code : " + nErrorCode); g).IF.
} 0JU+v:J[=
$ #bWh
o]TKL'gW
//停止文件下载 0S#T}ITm4Z
public void siteStop() wo5fGQJ
{ *('Vyd!n
bStop = true; P2g}G4qf
for(int i=0;i<nStartPos.length;i++) nO `R++
fileSplitterFetch.splitterStop(); SQ-CdpT<
T;sF@?
&Y jUoe
} aSt:G*a"
} MeDlsO
//负责部分文件的抓取 CPci 'SO
**FileSplitterFetch.java MnTqWC90
*/ !0X/^Xv@=
package NetFox; gt\*9P
tvcM< e20
D]?yGI_
import java.io.*; mGh8/Xt
import java.net.*; V6kJoSyde
s[Whg!2~
*]*0uo
public class FileSplitterFetch extends Thread { eOZ"kw"uHu
_j2q
JYrOE"!h
String sURL; //File URL ,m[#<}xXA
long nStartPos; //File Snippet Start Position j7yUya&
long nEndPos; //File Snippet End Position Bmv5yc+;
int nThreadID; //Thread's ID |h-e+Wh1
boolean bDownOver = false; //Downing is over @+yjt'B
boolean bStop = false; //Stop identical 8fA8@O}
FileAccessI fileAccessI = null; //File Access interface ( 9(NP_s
:X 9_~
$fAZ^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?X@uR5?{
{ k-I U}|Xz
this.sURL = sURL; \[<8AV"E-'
this.nStartPos = nStart; u9j1>QU
this.nEndPos = nEnd; h3j`X'
nThreadID = id; YQ`88z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r<!/!}fE,
} zxC~a97`
hVW1l&s
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public void run() \kP1Jr
{ G;AJBs>Y}
while(nStartPos < nEndPos && !bStop) 6+/BYN!&4
{ n!h952"
d,E2l~s
#D^(dz*
try{ VJS1{n=;k
URL url = new URL(sURL); "0m\y+%8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $GQ{Ai:VwF
httpConnection.setRequestProperty("User-Agent","NetFox"); />O.U?
String sProperty = "bytes="+nStartPos+"-"; iQvqifDmh
httpConnection.setRequestProperty("RANGE",sProperty); M3s:B& /
Utility.log(sProperty); ,U.|+i{
KqvM5$3
"ZP)[ [Rd
InputStream input = httpConnection.getInputStream(); kiu#THF
//logResponseHead(httpConnection); ^zKP5nzL
H=6-@+ !o
jH[{V[<#X
byte[] b = new byte[1024]; VEx )
int nRead; m%U$37A1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y4,t=Gq7^
{ GpXU&A'r
nStartPos += fileAccessI.write(b,0,nRead); zU";\);
//if(nThreadID == 1) %Mf3OtPiJW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TNlS2b1
} ~|&To>
q3ebps9^
wDKA1i%G
Utility.log("Thread " + nThreadID + " is over!"); G$t:#2
bDownOver = true; R<Ct{f!
//nPos = fileAccessI.write (b,0,nRead); @+hO,WXN
} b&!x.+d-z
catch(Exception e){e.printStackTrace ();} 9>ML;$T&
} .NMZHK?%
} TRFza}4:i
KSO%89R'
u_.Ig|Va
//打印回应的头信息 VKu|=m2vB
public void logResponseHead(HttpURLConnection con) USV;j%U4*
{ a 1~@m[
for(int i=1;;i++) b$Q#Fv&P
{ __i))2
String header=con.getHeaderFieldKey(i); oT- Y
if(header!=null) J:l%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IYe,VL
Utility.log(header+" : "+con.getHeaderField(header)); K<p)-q
else 9^@#Ua
break; u(~(+1W
} !BR@"%hx
} &"=<w
T1uOp5_]B
LT:8/&\
public void splitterStop() FrhI[D
{ 86W.z6
bStop = true; A>rN.XW
} 3-_`x9u*
iz2;xa*
9n;6;K#
} v K!vA-7
m'U>=<!D
)| F O>
/* A[H"(E#k
**FileAccess.java @VnK/5opS
*//文件访问(定位，写) rhC x&L
package NetFox; v\-7sgZR
import java.io.*; KA elq*
VujIKc#4
CPJ%<+4%b
public class FileAccessI implements Serializable{ DYTC2
bl[2VM7P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^F87gow%`B
RandomAccessFile oSavedFile; B1o*phM g
long nPos; W"H(HA
&'c&B0j
oA4<AJ2
public FileAccessI() throws IOException sK7b4gmK
{ ,R=)^Gh{
this("",0); 5)i+x-
} qTV.DCP
QoS]QY'bZ
`FmRoMW9+
public FileAccessI(String sName,long nPos) throws IOException T_oL/x_;
{ M! uE#|
oSavedFile = new RandomAccessFile(sName,"rw"); lGX8kAv?
this.nPos = nPos; K*N8Vpz(
oSavedFile.seek(nPos); 14yzGhA
} {$'oKJy*
dyt.(2
)pw53,7>aN
public synchronized int write(byte[] b,int nStart,int nLen) uwu`ms7z 2
{ +,J!xy+~,
int n = -1; 9%DLdc\z;
try{ j!K{1s[.y
oSavedFile.write(b,nStart,nLen); EB8<!c ?
n = nLen; ~Z5Wwp]a
} *P+8^t#Vp
catch(IOException e) te&p1F
{ ?e[]UO
e.printStackTrace (); J:0`*7
} U8n=Ro
Ns.{$'ll
h`:B8+k
return n; c4M]q4]F
} kjj?X|Un
iM"L%6*I^
W=2#Q2)
} <4%PT2R
goc"+K
NQ,2pM<*-
/* 9C|-|mo
**SiteInfoBean.java 3jw4#GW
*/ yi,Xs|%.
package NetFox; bqRO-\vO
'|nAGkA
K4^mG
public class SiteInfoBean { )gNVJ
e.]k4K
:YNXS;>)!
private String sSiteURL; //Site's URL :@J.!dokF
private String sFilePath; //Saved File's Path +6f[<^K#
private String sFileName; //Saved File's Name >/y+;<MZ
private int nSplitter; //Count of Splited Downloading File L%I8no-Q
[wcp2g3Px
;D}E/'=
public SiteInfoBean() lA,*]Mr~
{//nSplitter的缺省值为5 YH{FTVOt{C
//default value of nSplitter is 5 3'[ g2JR
this("","","",5); e# KP3Lp
} :jGgX>GG
TTz_w-68
[+b&)jN*2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %^bN^Sq -
{ DaqpveKa
sSiteURL= sURL; F,JqHa9
sFilePath = sPath; t8t+wi!
sFileName = sName; "^5%g%
this.nSplitter = nSpiltter; :tX,`G
{\ J%i|u
JmbWEX|
} =7-@&S=?s
hvF>Tu]^r
dA$qzQ
public String getSSiteURL() K"VRHIhfg
{ |%fM*F^7/
return sSiteURL; 6='x}Qb\H
} #)( D_*
pxHJX2
9^^:Y3j
public void setSSiteURL(String value) qfyuq]
{ _hi8mo
sSiteURL = value; `D0Hu!;
} *w6(nG'M{
}RZN3U=
;%PI
public String getSFilePath() 2~QN#u|UC3
{ P yN{
return sFilePath; zE]h]$oi
} =Y-mc#{8
b!z kQ?h
>e QFY^d5
public void setSFilePath(String value) HI{IC!6
{ nmUMg
sFilePath = value; o7v,:e:
} B-[qS;PY%
P30|TU+B
pFwhvw
public String getSFileName() CF/8d6}Vf
{ z460a[Wl
return sFileName; Mtq^6`JJ'
} 4_h?E:sBb
KNqs=:i
`_>44!M
public void setSFileName(String value) ^"EK:|Y4%K
{ yn.f?[G2
sFileName = value; <{1=4PA
} 48n7<M;I
N6%M+R/Q
swG!O}29OX
public int getNSplitter() y!jq!faqt
{ dR >hb*kJ
return nSplitter; ;7N~d TBQ
} S3> <zGYk
$;B0x
!s(s^
public void setNSplitter(int nCount) \Culf'iX
{ ,2lH*=m;
nSplitter = nCount; aYcc2N%C
} 9u] "($
} Oq*=oz^~1
)cYbE1=u8>
2G)q?_Q4S
/* &HJ'//bv
**Utility.java %q_b\K
*/ qp55U*
package NetFox; (sx,Ol
El|Y]f
]?(_}""1
public class Utility { *&~wl(+O=
</9@RO
eTZ2f
public Utility() {Zrf>ST
{ Gw?$.@L'I6
e6uVUzP4
FlepM*
} S~Yu;
n_Bi HMIU'
//线程睡眠 |RZI]H%
public static void sleep(int nSecond) zOA2chy4
{ C}(9SASs%
try{ m$B)_WW
Thread.sleep(nSecond); dn:/8~B"X
} 3Tz~DdB
catch(Exception e) D4\ * ,w
{ Q(h/C!rKe
e.printStackTrace (); M3c
} 9hdz<eFL
} |J^$3RX
}<g-0&GLm
//日志 y\c-I!6>26
public static void log(String sMsg) <F-W fR
{ C,nU.0
System.err.println(sMsg); H:.l:PJ
} MNd[Xzm
(5Sv$Xt
w~}.c:B
public static void log(int sMsg) 6'qu[~}Q
{ OmAa$L,'w
System.err.println(sMsg); 41NVF_R6J
} %mMPALN]{
} w}r~Wk^dLI
K#4Toc#=V
IhPX/P
/* QT7PCHP
**TestMethod.java *{s 3.=P.
*/ zE1=*zO`
package NetFox; q1vsvL9Q
>!%F$$
2~RG\JWTA
public class TestMethod { .Fm@OQr
^>m"j6`h,
|}naI_Qudv
public TestMethod() !\/J|~XZ
{ ///xx/weblogic60b2_win.exe G2!J`}
try{ @szr '&\%A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~dlpoT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z 3N'Xk
SiteFileFetch fileFetch = new SiteFileFetch(bean); 52#Ac;Y
fileFetch.start(); fe!{vrS
} ayh=@7*
catch(Exception e){e.printStackTrace ();} vw[i.af
D=:O^<
j/uu&\e
} 2^4OaHY88
)l[bu6bM
B8.uzX'p
public static void main(String[] args) 6uKS!\EY|
{ ;cp,d~mrf
new TestMethod(); XG}9)fT
} =9L1Z \f
} go B'C
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