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)); )7Gm<r
} 3_~V(a
for(int i=0;i<nEndPos.length-1;i++) s[NkPh9&
{ Oj\lg2Ck
nEndPos = nStartPos[i+1]; #Z)e]4{!l
} D'ZR>@w@
nEndPos[nEndPos.length-1] = nFileLength; hU3c;6]3
} [0El z@.C
} 6C4c.+S
a&6 3[p.<}
AIR,XlD
//启动子线程 U8-#W(tRR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /jaTH_Q),:
for(int i=0;i<nStartPos.length;i++) |Nd!+zE$Z
{ G)]'>m<y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K>l$Y#x}k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), & V^Z
nStartPos,nEndPos,i); H)}>&Z4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cKdn3 2Y4
fileSplitterFetch.start(); rE;*MqYt&
} yhJH3<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F$ShhZgi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V$VqYy9 *
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?>cx;"xF
nEndPos = " + nFileLength); q,F\8M\$
// fileSplitterFetch[nPos.length-1].start(); ri1D*CS
zR6,?Tzg
>0Y >T6!
//等待子线程结束 x:\+{-
//int count = 0; -;20|US)u
//是否结束while循环 ? [l[y$9
boolean breakWhile = false; .LhIB?
u)Y~+ [Q
BCYTlxC'
while(!bStop) %i{Z@
{ Qn(2UO!pD
write_nPos(); 9Bvi2 3
Utility.sleep(500); zflfV!vAg
breakWhile = true; ztTj2M"
]W~\%`#8?
-KhNsUQk
for(int i=0;i<nStartPos.length;i++) z0+LD
{ E;/WP!/.
if(!fileSplitterFetch.bDownOver) H?*EQK`7?0
{ u,AP$+Qk
breakWhile = false; B(7oHj.i2
break; 6=U81
} DDQ}&`s
} JFH3)Q
if(breakWhile) C-E~z{
break; )'+" y~
~U(`XvR\4
3O7]~5 j1
//count++; pYf57u
//if(count>4) -0r0M)
// siteStop(); k#uSH eq7f
} dv-L!C
M<^]Ywq*p
p.6C.2q~s]
System.err.println("文件下载结束！"); 5xC4lT/U
} s!,m,l[P
catch(Exception e){e.printStackTrace ();} uNCM,J!#~
} /4/'&tY
.DsdQ4Y
+Ac.@!X}%
//获得文件长度 ~k\Dde
public long getFileSize() WJWi'|C4
{ k-IL%+U
int nFileLength = -1; .2"-N5Z
try{ m:B9~lbT+
URL url = new URL(siteInfoBean.getSSiteURL()); ${m;x:'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V5:ad
httpConnection.setRequestProperty("User-Agent","NetFox"); yJQ>u
OL]P(HRm]~
VzfaUAIZl
int responseCode=httpConnection.getResponseCode(); h ` qlI1]
if(responseCode>=400) 0t*e#,y
{ \c}_!.xj"
processErrorCode(responseCode); K8#MQR2@
return -2; //-2 represent access is error k%uR!cL
} [As9&]Bv5
W*S}^6ZT`
"| Oj!&0
String sHeader; pHQrjEF*
"Vh3hnS~
p3r("\Za,
for(int i=1;;i++) GsIVx!
{ >[}lC7 z,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R !g'zS'
//Utility.log(in.readLine()); GWFF.Mo^
sHeader=httpConnection.getHeaderFieldKey(i); `_aX>fw
if(sHeader!=null) ICck 0S!
{ G0#<SJ,)
if(sHeader.equals("Content-Length")) SU,G0.
{ !LI6_Oq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JfD-CoQS'
break; wcH,!;3z+
} }uZ/^_U.
} aeZ$Wu>]W
else ')N[)&&Q{
break; 1WjNFi
} Zt_~Zxn3
} "<Ozoo1&w
catch(IOException e){e.printStackTrace ();} L4O.=*P1
catch(Exception e){e.printStackTrace ();} r{>Q{$Q
UE9RrfdN
#[f]-c(!
Utility.log(nFileLength); :eIi^K z[
<fHJ9(5$V
7Tb[sc'
return nFileLength; ^'9.VVyz
} w*?SGW
dG&^M".(
>{6U1ft):
//保存下载信息（文件指针位置） ~c,CngeL0
private void write_nPos() nuKcq!L
{ Gj_7wP$
try{ m)7Ql!l
output = new DataOutputStream(new FileOutputStream(tmpFile)); vB74r]'F
output.writeInt(nStartPos.length); !3F3E8%
for(int i=0;i<nStartPos.length;i++) Su/8P[q_
{ (1EtC{ m
// output.writeLong(nPos); 6VUs:iO1j5
output.writeLong(fileSplitterFetch.nStartPos); ZnKjU ]m
output.writeLong(fileSplitterFetch.nEndPos); IG+g7kDCY
} s\+| ql
output.close(); mT:NC'b<9
} GP>\3@>
catch(IOException e){e.printStackTrace ();} ;b{yu|
catch(Exception e){e.printStackTrace ();} SzP`(}AU
} NSawD.9mV
!"2S'oQKS
oyB gF\
//读取保存的下载信息（文件指针位置） }y%c.
private void read_nPos() J>l?HK
{ apOXcZ
try{ xKR\w!+Z'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &(7=NAQsE
int nCount = input.readInt(); dI%?uk
nStartPos = new long[nCount]; +0}z3T1L
nEndPos = new long[nCount]; SR$ 'JGfp
for(int i=0;i<nStartPos.length;i++) _aeIK
{ t4iD<{4
nStartPos = input.readLong(); [rkw k\m*
nEndPos = input.readLong(); lihIPMU
} @)\4 $#+-
input.close(); nb<e<>L
} u,V_j|(e
catch(IOException e){e.printStackTrace ();} T;G<62`.h
catch(Exception e){e.printStackTrace ();} {J1iheuS}
} %afN&T
hkb&]XWi[
9tX+n{i
private void processErrorCode(int nErrorCode) Zg$S% 1(Q
{ i;rcgd
System.err.println("Error Code : " + nErrorCode); )I#{\^
} mC0_rN^Aj
-"NK"nb
#c!rx%8I
//停止文件下载 Oa2\\I
public void siteStop() zuu<;^/R
{ -Bl]RpHCe
bStop = true; lA%FS]vh
for(int i=0;i<nStartPos.length;i++) X n8&&w"
fileSplitterFetch.splitterStop(); jDb"|l
Jz}`-fU`
VKkvf"X
} QM![tZt%;
} o\F>K'
//负责部分文件的抓取 a:8 MoH4
**FileSplitterFetch.java Bn9#F#F<
*/ m]vS"AdX
package NetFox; m/Erw"Z
hq&|
"~=-Q#xO
import java.io.*; Nm !~h|3
import java.net.*; [YP{%1*RM
[GPCd@
NVghkd
public class FileSplitterFetch extends Thread { CY*o"@-o5)
DK eB%k
^2H;
String sURL; //File URL dB6['z)2
long nStartPos; //File Snippet Start Position tKS[
long nEndPos; //File Snippet End Position _RzFh
int nThreadID; //Thread's ID n$`+03a
boolean bDownOver = false; //Downing is over |p!($
boolean bStop = false; //Stop identical ufCpX>lNF
FileAccessI fileAccessI = null; //File Access interface e!PB3I
%ufh
NT0n[o^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]J[d8S5
{ .XqeO@z
this.sURL = sURL; 81"` B2
this.nStartPos = nStart; =n5n
this.nEndPos = nEnd; _Dd>e=v
nThreadID = id; 5F+G8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m~ 5"q%;
} cF4,dnI
aZ$5"
Y0.'u{J*
public void run() z3]W #
{ }tw+8YWkz
while(nStartPos < nEndPos && !bStop) u7^(?"x
{ ;W+8X-B
P3`$4p?
0PqI^|!
try{ qEuO@oE
URL url = new URL(sURL); s;YbZ*oaMe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {1Y@%e
httpConnection.setRequestProperty("User-Agent","NetFox"); od{\z
String sProperty = "bytes="+nStartPos+"-"; 0 zK{)HZ
httpConnection.setRequestProperty("RANGE",sProperty); q8&l%-d`
Utility.log(sProperty); xu_,0ZT]{
'B{FRK
[al$sCD]+
InputStream input = httpConnection.getInputStream(); A+!,{G
//logResponseHead(httpConnection); r88De=*
`<yQ`Y_X
Cdib{y<ji
byte[] b = new byte[1024]; L-}J=n\
int nRead; 5wmd[YL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~5`oNa
{ 5?F5xiW
nStartPos += fileAccessI.write(b,0,nRead); ^P^%Q)QXl
//if(nThreadID == 1) e*qGrg(E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -&sY*(:n_
} t))MZw&@
;:j1FOj
HO['o{>BL
Utility.log("Thread " + nThreadID + " is over!"); hO&b\#@~
bDownOver = true; CxeW5qc
//nPos = fileAccessI.write (b,0,nRead); `:Gzjngc
} JC%&d1
catch(Exception e){e.printStackTrace ();} 4MS#`E7LrC
} s:7/\h
} h Fik>B#!
0W}qp?
9M;t4Um
//打印回应的头信息 RSe4lw
public void logResponseHead(HttpURLConnection con) (z>t4(%\
{ R?O)vLmd
for(int i=1;;i++) 6IG?t
{ Kc?4q=7q
String header=con.getHeaderFieldKey(i); ^L5-2;s<U'
if(header!=null) 3q}j"x?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fCx(
Utility.log(header+" : "+con.getHeaderField(header)); +x=)Kp>
else t|eH'"N%o
break; _ Lb"yug
} gr*CN<
} '"fJA/O
q6)fP4MQ]
kFwFPK%B
public void splitterStop() _%- +"3Ll
{ !CWe1Dm
bStop = true; 5K ;E*s,
} 29,ET}~
IGcq*mR=
s@ r{TXEn
} s{Y4wvQyB
'1:)q
vUJ;D
/* 8Rwk o6x
**FileAccess.java u*G<?
*//文件访问(定位，写) a&x:_vv
package NetFox; )^ Y+Vn
import java.io.*; X n$ZA-
R,G*]/r`
qU7_%Z
public class FileAccessI implements Serializable{ iCF},W+
Y@0'0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SOhM6/ID2/
RandomAccessFile oSavedFile; e4YP$}_L
long nPos; )&c#?wx'w
:rUMmO-
L"|Bm{Run
public FileAccessI() throws IOException X`KSj N&(
{ 3NtUB;!
this("",0); cx$IWQf2
} ]a4U\yr
M_};J;
cdt9hH`Cd
public FileAccessI(String sName,long nPos) throws IOException l,7& z
{ p0bWzIH
oSavedFile = new RandomAccessFile(sName,"rw"); ZOqS"3j! j
this.nPos = nPos; x%=CEe?6
oSavedFile.seek(nPos); FAEF
} ]8\I{LR
8u+kA mI
N s+g9+<A
public synchronized int write(byte[] b,int nStart,int nLen) g0tnt)]
{ Nnl3r@
int n = -1; YpDJ(61+
try{ z6iKIw $
oSavedFile.write(b,nStart,nLen); 25)9R^
n = nLen; TC?B_;a
} P9bM+@5e
catch(IOException e) $V(]z`b&
{ TU0-L35P1
e.printStackTrace (); D=-}&w_T"
} #[#evlr=
jW\:+Taq
AU$~Ap*rsa
return n; [yXmnrxA
} f1MRmp-f'
TVD~Ix
`F7]M
} =\oH= f
}tW-l*\U
%+(AKZu:
/* t]LiFpy2IC
**SiteInfoBean.java a:)FWdp?9
*/ R ZY=c
package NetFox; vmqa_gU\
@'R)$:I%L
{Yj5Mj|#
public class SiteInfoBean { N `|A
'Rn-SD~gIr
EL?(D
private String sSiteURL; //Site's URL 'QCIKCn<
private String sFilePath; //Saved File's Path :5NMgR.d
private String sFileName; //Saved File's Name /I`TN5~
private int nSplitter; //Count of Splited Downloading File 6h;(b2p{
8)X9abC
c* {6T}VZr
public SiteInfoBean() zuvPV{ X
{//nSplitter的缺省值为5 tK%ie\
//default value of nSplitter is 5 fjRVYOG#
this("","","",5); OUv<a`0
} pLB2! +
UCLM*`M
1INX#qTZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z'q~%1t
{ S}@7Z`
sSiteURL= sURL; NKO"'
sFilePath = sPath; }`"}eN @,
sFileName = sName; 0^ODJ7
this.nSplitter = nSpiltter; fu"cX;
kamQZzPe
)d2Z g
} 1B~O!']N<
>v:ex(y0
ra$:ibLN
public String getSSiteURL() PJ.\)oP
{ E]@&<TFq
return sSiteURL; +F;2FD$
} Cr5ND\
v~nKO?{
E\[BE<y
public void setSSiteURL(String value) 3oCI1>k
{ o1.~g'!^
sSiteURL = value; ${ {4L?7
} +U oNJ
o<Zlm)"%1
*)RmX$v3
public String getSFilePath() ;kgP:n
{ 2)f_L|o,m
return sFilePath; _?c.m*)A
} VgHO&vU
,;g%/6X
P@7>R7gS
public void setSFilePath(String value) <0CjEsAB]
{ rnIjpc F
sFilePath = value; #A/OGi
} ")Fd'&58
-r\jIO_
>yO/p(/;jR
public String getSFileName() {iD/0q
{ <]rayUyaf
return sFileName; l/N<'T_G
} NL9.J@"b
?v2_7x&
/q9I^ztV
public void setSFileName(String value) gu k,GF9p]
{ 5|H;%T3_
sFileName = value; ,!:c6F+
} UleT9 [M
$BwWQ?lp
hi8q?4jE
public int getNSplitter() c!Hz'W
{ Bz]tKJ
return nSplitter; <o(;~
} t<!m4Yd|#
fd)8lK[KJ"
R]"Zv'M(AM
public void setNSplitter(int nCount) qezWfR`
{ 6Og@tho
nSplitter = nCount; (?qCtLZ
} A0{xt*g
} t!?`2Z5
uMcI'=
'm`O34h
/* '.|}
**Utility.java `^)`J
*/ Ik:G5m<ta
package NetFox; `cGks
I-#!mFl
u+)!C*ho
public class Utility { mY 1l2
=Vg~ VD
yq~
public Utility() r^,_m,s'<
{ b<u\THy#
eb_.@.a
.}dLqw
} /uw@o9`~2-
j7P49{
//线程睡眠 QV[&2&&^<<
public static void sleep(int nSecond) yX&# rI
{ D2ggFxqe
try{ a ,mgM&yD
Thread.sleep(nSecond); ?_]Y8f
} wkt4vE87
catch(Exception e) Zo=,!@q(
{ Ab$E@H#
e.printStackTrace (); )q$[uS_1[
} eXl?f_9
} #(]D]f[@
r]e{~v/
//日志 2zj` H9
public static void log(String sMsg) SzLlJUVX
{ HYl+xH'.j
System.err.println(sMsg); %pZT3dcK
} "@x(2(Y&
i;HXz`vT7
WyV4p
public static void log(int sMsg) *JOK8[Qn
{ I"]E}nd)
System.err.println(sMsg); KDN#CU
} L4iWR/&
} ?c.\\2>|F
HVM%B{(
I(6%'s2
/* /qQx~doK
**TestMethod.java '&CZ%&(Gw
*/ i3 js'?7E
package NetFox; Dk\%,[4(
IQBL;=.J.
:lu!%p<$
public class TestMethod { B} qRz
(CQ! &Z8
m]DP{-s4
public TestMethod() {JWixbA
{ ///xx/weblogic60b2_win.exe T)tr"<F5NP
try{ Q}&'1J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yK{P%oh)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RlfI]uCDM
SiteFileFetch fileFetch = new SiteFileFetch(bean); {r&r^!K;
fileFetch.start(); Nr@,In|JS
} CX#d
catch(Exception e){e.printStackTrace ();} !d##q)D f?
$Y/z+ea
0+0Y$;<
} nu^@}|UG
y95 #t
/8Lb_QH{
public static void main(String[] args) .Z7tE?
{ GUQ3XF\
new TestMethod(); ,5 ,r.
} []OS p&
} Va[&~lA)
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