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)); Fqr}zR)
} v7Q=
for(int i=0;i<nEndPos.length-1;i++) 6xfG`7Az
{ "V7 SB
nEndPos = nStartPos[i+1]; s01W_P.@R
} {Kdr-aC
nEndPos[nEndPos.length-1] = nFileLength; vBRW5@
} s"jNS1B
} fQ.{sQ$@h
|~V`Es +j
'5V#sq;Z
//启动子线程 m`3Mev
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g#Doed.30=
for(int i=0;i<nStartPos.length;i++) Lc0yLm
{ <Oyxzs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :f9O3QA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >R&=mo~
nStartPos,nEndPos,i); N7}Y\1-8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cbHb!Lbg
fileSplitterFetch.start(); 3B+ F'k&#
} Tw)"#Y!T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /d/Quro
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #"3az8u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <;T$?J9
nEndPos = " + nFileLength); {\87]xJ
// fileSplitterFetch[nPos.length-1].start(); Hf^Tok^6@]
z'9Mg]&>
cag9f?w@V
//等待子线程结束 0nX.%2p#Je
//int count = 0; kVG]zt2
//是否结束while循环 NEY b-#v
boolean breakWhile = false; h3z=tu['
xQKD1#y
?n]e5R(cj
while(!bStop) (l~3~n
{ Vv]81y15Q;
write_nPos(); q%^vx%aL\
Utility.sleep(500); MZ/PXY
breakWhile = true; #c2InwZV
C/sDyv$
r]0UF0#
for(int i=0;i<nStartPos.length;i++) [u=DAk?8
{ K9BoIHo
if(!fileSplitterFetch.bDownOver) TAXl73j_CY
{ fUJ\W"qya
breakWhile = false; pPezy:
break; l}Fa-9_'
} m4@f&6x
} p| #gn<z}
if(breakWhile) O8J:Tw}M*
break; *C0gpEf9S
CYxrKW l:'
SdI/
//count++; N]p|c3D
//if(count>4) <;?&<qMo,P
// siteStop(); FyZiiH4|
} zF F=v7[j
UpA{$@
jE&Onzc
System.err.println("文件下载结束！"); te+5@k#t
} iN}BMd.U
catch(Exception e){e.printStackTrace ();} <_|H]^o
} bnWKfz5
T21SuM
!`VO#_TJ
//获得文件长度 &M,"%w!
public long getFileSize() BBg&ZIYEh
{ F[ Itq
int nFileLength = -1; HxVQeyOR
try{ })l+-H"
URL url = new URL(siteInfoBean.getSSiteURL()); yk5T"#'+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }UzO_&Z#6
httpConnection.setRequestProperty("User-Agent","NetFox"); <IF\;,.c
Kk^tQwj/QE
jaoGm$o>"F
int responseCode=httpConnection.getResponseCode(); mndUQN_Gb
if(responseCode>=400) o6} +5
{ mQ9%[U,
processErrorCode(responseCode); \E'Nk$V3
return -2; //-2 represent access is error D4"](RXH
} h=3156M
MRB>(}
W biUz2)
String sHeader; V zx%N.
S*H :/Ip
bW`@9 =E
for(int i=1;;i++) n9zS'VU
{ \w 6%J77
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !(!BW9Zt+
//Utility.log(in.readLine()); 6]|NB&
sHeader=httpConnection.getHeaderFieldKey(i); V.IgEE]
if(sHeader!=null) ,x+_/kqx
{ ax0:v!,e
if(sHeader.equals("Content-Length")) {C%/>e2-%
{ N_vVEIO9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u+]v.Mt
break; |wf:|%
} zS:89y<
} lPS A
else t9&z|?Vz
break; Bc4{$sc"O
} J! 4l-.-
} '_n{+eR74
catch(IOException e){e.printStackTrace ();} dt"[5;_P`
catch(Exception e){e.printStackTrace ();} VA _O0y2
Ih}I`wY-
mI=^7'Mk
Utility.log(nFileLength); b'$j* N
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XR^VRn6O
return nFileLength; b; SFnZa8
} S.+)">buH
V*l0|,9
4/{Io &|
//保存下载信息（文件指针位置） ~'WvIA (
private void write_nPos() iSxxy1R
{ 1K'0ajl1A
try{ q{UP_6OF
output = new DataOutputStream(new FileOutputStream(tmpFile)); a9GOY+;bf
output.writeInt(nStartPos.length); b`n+[UCPtn
for(int i=0;i<nStartPos.length;i++) DPnKr/
{ {uO8VL5+Qx
// output.writeLong(nPos); 9p!V?cH#8
output.writeLong(fileSplitterFetch.nStartPos); !MB%
output.writeLong(fileSplitterFetch.nEndPos); &7 }!U
} gKg2Ntxj
output.close(); 8w|j Z@
} G'( %8\
catch(IOException e){e.printStackTrace ();} .2hQ!)+
catch(Exception e){e.printStackTrace ();} vi6EI wZG
} }>xgzhdT
~(B\X?v
_Z6/r^c
//读取保存的下载信息（文件指针位置） r0kA47
private void read_nPos() J+&AtGq]u
{ J p .wg
try{ CF^7 {g(y_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =~Jv*c
int nCount = input.readInt(); RlX;c!K
nStartPos = new long[nCount]; L6j 5pI
nEndPos = new long[nCount]; $*%Ml+H-
for(int i=0;i<nStartPos.length;i++) uLb- NxQ-
{ dUn8Xqj1
nStartPos = input.readLong(); Ms(;B*
nEndPos = input.readLong(); kq:,}fc;B
} 9B'l+nP
input.close(); i~z:Fe{
} >"F~%D<.
catch(IOException e){e.printStackTrace ();} Ta!.oC[
catch(Exception e){e.printStackTrace ();} Ts;W,pgP
} JBE'B Q@
/,5`#Gte_
>w9)c|
private void processErrorCode(int nErrorCode) ##u+[ !
{ xP'IyABx
System.err.println("Error Code : " + nErrorCode); =rgWOn8
} #'<I!G
AnPm5i.
/[[zAq{OA
//停止文件下载 N)RWC7th{
public void siteStop() _OcgD<
{ ;ijJ%/
bStop = true; "JVzv U]
for(int i=0;i<nStartPos.length;i++) D +)6#i Y
fileSplitterFetch.splitterStop(); (eJr-xZ/
$t1]w]}d
SlZL%C;
} `+B+RQl}[
} S M987Y!B
//负责部分文件的抓取 j1YE_U
**FileSplitterFetch.java Q|gun}
*/ D5T\X-+]O
package NetFox; ; Z61|@Y
]-%ZN+
yixW>W}
import java.io.*; WGG|d)'@
import java.net.*; B0q![
8t}=?:B+{
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public class FileSplitterFetch extends Thread { "MC&!AMv
h%+8}uywZ
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String sURL; //File URL <$Uj ~jN
long nStartPos; //File Snippet Start Position r'&9'rir2
long nEndPos; //File Snippet End Position 9aZ3W<N`M
int nThreadID; //Thread's ID kc8GnKM&mc
boolean bDownOver = false; //Downing is over Q(k$HP
boolean bStop = false; //Stop identical B[4y(Im
FileAccessI fileAccessI = null; //File Access interface $'9r=#EH
DGHX:Ft#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gSR&CnqZ<
{ dhK$XG
this.sURL = sURL; a4`@z:l
this.nStartPos = nStart; &%qD Som3
this.nEndPos = nEnd; )r?i^D&4
nThreadID = id; \U !<-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4N$svA
} .[2MPjg
f[.hN
0A?w,A`"
public void run() a' #-%!]
{ Q(]-\L'
while(nStartPos < nEndPos && !bStop) &1Cq+YpI
{ d'[aOH4}
0E\R\KO$>
D4'XBXmb
try{ '12|:t&7
URL url = new URL(sURL); wmo'Pl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =53LapTPJ
httpConnection.setRequestProperty("User-Agent","NetFox"); 3<mv9U(
String sProperty = "bytes="+nStartPos+"-"; ~d5"<`<^o
httpConnection.setRequestProperty("RANGE",sProperty); RX2= iO"
Utility.log(sProperty); 1v2wP2]|;
sgX}`JH?z
w,}}mC)\*
InputStream input = httpConnection.getInputStream(); n"FOCcTIs
//logResponseHead(httpConnection); g+k6pi*
)&dhE^ O
d}l^yln
byte[] b = new byte[1024]; cC}s5`
int nRead; @bqCs^U35
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3Vw%[+lY9
{ J1R%w{
nStartPos += fileAccessI.write(b,0,nRead); &-b=gnT
//if(nThreadID == 1) *?K`T^LS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oQyG
} .k*2T<p$rC
)D[xY0Y~
Z,4=<;PF
Utility.log("Thread " + nThreadID + " is over!"); t91CxZQ^s
bDownOver = true; f2yv7t T
//nPos = fileAccessI.write (b,0,nRead); =]zPUzr,|
} iL,3g[g
catch(Exception e){e.printStackTrace ();} ItaJgtsV
} B:mlBSH
} yPQ{tS*t
+'n1?^U
/pk;E$qv
//打印回应的头信息 jQ^Ib]"K
public void logResponseHead(HttpURLConnection con) _-!6@^+
{ O4E2)N
for(int i=1;;i++) |@ldXuYb
{ R3@iN&
String header=con.getHeaderFieldKey(i); =oh6;Ojt
if(header!=null) XdS<51 C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /GeS(xzQ
Utility.log(header+" : "+con.getHeaderField(header)); ZDDwh&h
else sQ)4kF&,
break; .86..1
} A.h?#%TLL
} Xj@Kt|&`k
?x[>g!r
kW:!$MX!
public void splitterStop() a<o0B{7{BM
{ y]CJOC)/K
bStop = true; {(q Un
} Bhs`Y/Ls-
)?xt=9Lh
hqds T
} _x'StD
+nZG!nP
hN:Z-el
/* lLDHx3+
**FileAccess.java iIF'!K=q
*//文件访问(定位，写) mY AFruN
package NetFox; >L;O, {Px-
import java.io.*; % (.PRRI
3PEs$m9e
6,h<0j{
public class FileAccessI implements Serializable{ 2kgm)-z
0jzA\$oD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5 O6MI4:
RandomAccessFile oSavedFile; FD-)nv2:
long nPos; b;O+QRa
:_H88/?RR
*&PgDAQ
public FileAccessI() throws IOException n^%u9H
{ A+l"
this("",0); s-ou;S3s
} A^Zs?<C-
0x &^{P~
'oEmbk8Hg
public FileAccessI(String sName,long nPos) throws IOException gJ7$G3&oZg
{ 4HHf3j!5
oSavedFile = new RandomAccessFile(sName,"rw"); <f*0 XJ#
this.nPos = nPos; qXF"1f_+
oSavedFile.seek(nPos); S-H3UND"
} W!(Q_B
(BGipX4
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public synchronized int write(byte[] b,int nStart,int nLen) K%k,-
{ 4<Y?#bm'
int n = -1; 1_QO>T'
try{ h`Mf;'P
oSavedFile.write(b,nStart,nLen); k$2Y)
n = nLen; 6GN'rVr!Z
} hJ@nW5CI
catch(IOException e) {HU48v"W
{ 'YeJGzsJp
e.printStackTrace (); A^7!+1*K+
} 6{~I7!m"
RW)C<g
L; ~=(
return n; !v`=EF.
} cjW]Nw
[Wh 43Z
;4bu=<%
} 8dH|s#.4um
;1 fML,8
Pla EI p
/* Txh;r.1e
**SiteInfoBean.java jZ;T&s
*/ <gy'@w?
package NetFox; 0d2%CsMS"D
t|m3b~Oyv
r:cUAe7#
public class SiteInfoBean { x,%&[6(
S@#L!sT`u
D4|_?O3|m
private String sSiteURL; //Site's URL WKf~K4BL>
private String sFilePath; //Saved File's Path I}WJ0}R
private String sFileName; //Saved File's Name ;'p'8lts
private int nSplitter; //Count of Splited Downloading File j$^]WRt
5ZVTI,4K
k.ZfjX"
public SiteInfoBean() ^bG!k]U!2
{//nSplitter的缺省值为5 +9X[gef8
//default value of nSplitter is 5 UPYM~c+}
this("","","",5); bqO"k t
} L7-nPH
nM`)`!/
3^Zi/r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?q P}=nJ
{ dq(x@&J
sSiteURL= sURL; H.L@]~AyL
sFilePath = sPath; /HRaX!|E#
sFileName = sName; x_K%
this.nSplitter = nSpiltter; ^XM;D/Gp~
]`prDw'
m C Ge*V}
} f<wgZM
Tt\w^Gv\d
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public String getSSiteURL() [P/gM3*'
{ v(iUo&Ge
return sSiteURL; * 5n:+Tw(
} J%)2,szn0
w%;'uN_
lI 1lP 1
public void setSSiteURL(String value) lNb\^b
{ Z3dd9m#.]
sSiteURL = value; B/OO$=>(
} V1.F`3h~
)a\h5nQI)
}U9jsm
public String getSFilePath() N6;Z\\&0^q
{ u$#7W>R
return sFilePath; 1RA$hW@}
} }El_.@'T &
!U_L7
l i-YkaP
public void setSFilePath(String value) kP$gl|
{ 37xxVbik
sFilePath = value; F6p1 VFs
} aTsfl
0K ?(xB
YHYB.H)
public String getSFileName() {O)&5
{ Z<W6Avr
return sFileName; E6:p
} ^A`(
M;qL)vf
Gq/6{eRo\
public void setSFileName(String value) k5D'RD
{ ;L2bC3
sFileName = value; LltguNM$
} pm\X*t}L
}eM<A$J
BA,6f?ktXS
public int getNSplitter() s.'\&B[
{ Z@!W?Ed
return nSplitter; I&8m5F?$`
} I})t
070IBAk}_
z :v, Vu
public void setNSplitter(int nCount) -G#k/Rz6
{ sG2 3[t8
nSplitter = nCount; E]U0CwFtr
} `Xdxg\|
} KVxb"|[
/T)n5X
acQNpT
/* ; ,jLtl
**Utility.java ~qxXou,J
*/ Y&+_p$13
package NetFox; aG_ON0g
:)95 b fa.
mwH!:f
public class Utility { x9l0UD*+g
mo[<4Uks
2F@)nh
public Utility() d~-p;i
{ *)1Vs'!-
Wxau]uix
[P=[hj;
} o!`O i5
orH0M!OtS!
//线程睡眠 {$YD-bqY
public static void sleep(int nSecond) Cfo 8gX*
{ Lo5@zNt%W
try{ y[6&46r7D
Thread.sleep(nSecond); 1Dp@n
} _G #"B{7
catch(Exception e) ;+34g6
{ ]^jdO##M
e.printStackTrace (); u#WTh%/
} W#I:j: p
} ,M.!z@
qlITQKGG
//日志 7'i#!5
public static void log(String sMsg) 6\fMzm
{ &v5.;8u+OV
System.err.println(sMsg); _iJXp0g
} :dIQV(iW
?%/u/*9rj
X2dc\v.x
public static void log(int sMsg) ^y0C5Bl;
{ )S};k=kG
System.err.println(sMsg); )9L pX
} F4E3c4 81
} lkH;N<U
ct4 [b|
i4zV(
/* Qy5Os?9"
**TestMethod.java D?yE$_3>c
*/ H9VXsFTW
package NetFox; rp @
dMs||&|&
{{*]bGko
public class TestMethod { 6w"( y~c1
@D~+D@i$TW
'nWs0iH.
public TestMethod() }"?nU4q;S
{ ///xx/weblogic60b2_win.exe Zxc7nLKF~
try{ (s$u_aq77
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4 %)N(%u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $.Q>M]xH
SiteFileFetch fileFetch = new SiteFileFetch(bean); q@!'R{fu
fileFetch.start(); "WbVCT'i
} g(1B W#$
catch(Exception e){e.printStackTrace ();} AR~$MCR]"k
=v4r M0m,
y(nsyA
} VP%i1|XZJ
%7v@n+Q
!Wixs]od
public static void main(String[] args) + sywgb)
{ &^7uv0M<y
new TestMethod(); jc&/}o$K
} }\f(qw
} qfGtUkSSb
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