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)); u%lUi2P2E
} kP'm$+1or
for(int i=0;i<nEndPos.length-1;i++) UD.ZnE{"
{ efE=5%O
nEndPos = nStartPos[i+1]; ":q+"*fy
} T8&eaAoo
nEndPos[nEndPos.length-1] = nFileLength; 97~>gFU77#
} TZGk[u^*
} jFip-=T{4
e<(6x[_
o1"N{Eu
//启动子线程 hA;Ai:8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c,O;B_}M]
for(int i=0;i<nStartPos.length;i++) +TX4,"
{ yFS{8yrRUU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RR'sW@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #c":y5:
nStartPos,nEndPos,i); =:!>0~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); __zHe-.m
fileSplitterFetch.start(); 9C=*>I27?
} _#MKpH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /DP0K @%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8_o~0lb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |5ge4,}0
nEndPos = " + nFileLength); i=1crJ:
// fileSplitterFetch[nPos.length-1].start(); EJRkFn8XG'
Ke=+D'=
oz]&=>$1I
//等待子线程结束 \ \Tz'>[\
//int count = 0; D[}^G5
//是否结束while循环 f/s"2r
boolean breakWhile = false; UR9\g(
,7k-LAA
zG8g}FrzG;
while(!bStop) NqGSoOjIO2
{ O&&_)
write_nPos(); ~<~ ~C#R
Utility.sleep(500); 74N3wi5B
breakWhile = true; Z`86YYGK
TI\xCIH
?>iUz.];t
for(int i=0;i<nStartPos.length;i++) U=7nz|
{ z@w}+fYO
if(!fileSplitterFetch.bDownOver) La3rX
{ k{=dV
breakWhile = false; +S[3HX7H
break; Lis>Qr
} 13w(Tf
} 4T;<`{]
if(breakWhile) # 5U1F[
break; M] +.xo+A
bM5o-U#^ C
d0C _:_
//count++; U]w"T{;@.)
//if(count>4) wW/q#kc
// siteStop(); X/90S2=P
} O|)b$H_
z1 MT@G)S$
"^!y>]j#A
System.err.println("文件下载结束！"); *,%$l+\h
} u`.)O2)xU
catch(Exception e){e.printStackTrace ();} uv<_.Jq]
} zx,9x*g
So8 Dwz?
psc Fb$b
//获得文件长度 i;s;:{cn
public long getFileSize() Pr(@&:v:
{ m(}}%VeR"z
int nFileLength = -1; 2
try{ &6 <a<S
URL url = new URL(siteInfoBean.getSSiteURL()); h_+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PB7-`uz
httpConnection.setRequestProperty("User-Agent","NetFox"); j;7E+Yp
Bf]Bi~w<
"P54|XIJ\
int responseCode=httpConnection.getResponseCode(); gzqp=I[%
if(responseCode>=400) Wz"H.hf
{ Kop(+]Q&n
processErrorCode(responseCode); -zn_d]NV
return -2; //-2 represent access is error 5V\",PAW
} JAP(J~
B2P@9u|9
CaO-aL
String sHeader; ZTz07Jt
|FM*1Q[1
<Z<meB[g
for(int i=1;;i++) 4OQ,|Wm4G
{ h.F=Fhx/1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k4hk* 0Jq
//Utility.log(in.readLine()); MpGG}J[y
sHeader=httpConnection.getHeaderFieldKey(i); j7Ts&;`[*
if(sHeader!=null) rUmP_
{ S*|/txE'~Y
if(sHeader.equals("Content-Length")) \!BVf@>p%
{ .UNV &R0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !U>WAD9
break; /*k_`3L
} jl&Nphp
} wT6zeEV~*
else <F;+A{M)
break; `]XI Q\ *
} Iv*\8?07)
} _oCNrjt9
catch(IOException e){e.printStackTrace ();} {\%I;2X
catch(Exception e){e.printStackTrace ();} XD|g G
~6@`;s`[Y
k4dC
Utility.log(nFileLength); !|i #g$
;H.V-~:P)
+kQ=2dva
return nFileLength; ^]D1':
} \`xlD&F@U
%)?jaE}[
7>BfHb
//保存下载信息（文件指针位置） w4Df?)Z
private void write_nPos() G$MEVfd"
{ `o295eiY(b
try{ la_c:#ho
output = new DataOutputStream(new FileOutputStream(tmpFile)); -~lq <M
output.writeInt(nStartPos.length); xk% 62W
for(int i=0;i<nStartPos.length;i++) 25-h5$s
{ 5TB6QLPEwY
// output.writeLong(nPos); 0kOwA%m
output.writeLong(fileSplitterFetch.nStartPos); ;l0dx$w
output.writeLong(fileSplitterFetch.nEndPos); Z%:>nDZV
} S6JXi>n
output.close(); KNd<8{'.
} L/exR6M7
catch(IOException e){e.printStackTrace ();} /\h*v!:
catch(Exception e){e.printStackTrace ();} ?_^{9q%9
} Q N#bd~
_UPfqC ?
o!KDeY
//读取保存的下载信息（文件指针位置） ""a$[[ %WC
private void read_nPos() #0[^jJ3J
{ wN4#j}C
try{ ]lBCK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dp'[I:X
int nCount = input.readInt(); ceJi|`F
nStartPos = new long[nCount]; ?X6}+
nEndPos = new long[nCount]; ]4en|Aq
for(int i=0;i<nStartPos.length;i++) n"6L\u
{ XDPgl=~
nStartPos = input.readLong(); (H !iK,R
nEndPos = input.readLong(); l[ $bn!_e
} & rab,I"
input.close(); 1VlU'qY
} L}Y.xi
catch(IOException e){e.printStackTrace ();} jJNCNH*0
catch(Exception e){e.printStackTrace ();} y"q>}5
} _7<{+Zzm
jxkjPf?
s{yw1:
private void processErrorCode(int nErrorCode) %}VH5s9\
{ D4[t^G;J
System.err.println("Error Code : " + nErrorCode); {ptHk<K:)
} ,Q7;(&x~
?V^7`3F
>!xyA;
//停止文件下载 /0XMQy
public void siteStop() Tgr,1)T
{ ()l3X.t,$
bStop = true; ~BmA!BZV`
for(int i=0;i<nStartPos.length;i++) ji1vLu4|t
fileSplitterFetch.splitterStop(); yW=+6@A4
C$1W+(
]>VG}e~b
} A+0-pF2D
} r.\L@Y<
//负责部分文件的抓取 K8&;B)VT>
**FileSplitterFetch.java % (y{Sca
*/ #6<1 =I'j
package NetFox; OpEH4X.Z
?e<2'\5v
z m$Sw0#(
import java.io.*; HT.*r6Y>g
import java.net.*; `IUn{I
UE.kR+1
KaNs>[a8
public class FileSplitterFetch extends Thread { Z%qtAPd
3>aEP5
2.Qz"YDh =
String sURL; //File URL ?zf3Fn2y
long nStartPos; //File Snippet Start Position zR^Gy"
long nEndPos; //File Snippet End Position i9DD)Y<
int nThreadID; //Thread's ID M>]A!W=
boolean bDownOver = false; //Downing is over -9i7Ja
boolean bStop = false; //Stop identical sE6>JaH
FileAccessI fileAccessI = null; //File Access interface aLGq<6Ja
Lr$Mk#'B
|j`73@6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c Rq2 re
{ jRS{7rx%MH
this.sURL = sURL; `Zm6e!dH-
this.nStartPos = nStart; WI/tWj0
this.nEndPos = nEnd; Ec@n<KK#
nThreadID = id; 2+ cs^M3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P.,U>m
} 6p)AQTh>
@a?7D;+<
5dj@N3ZX7;
public void run() a,c!#iyl3
{ 9_?xAJ
while(nStartPos < nEndPos && !bStop) WK>|IgK
{ ^Fco'nlM
nTEN&8Y>R
Gs,:$Im
try{ -V|"T+U
URL url = new URL(sURL); F^75y?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0 Uropam
httpConnection.setRequestProperty("User-Agent","NetFox"); &xQM!f
String sProperty = "bytes="+nStartPos+"-"; 3c=kYcj
httpConnection.setRequestProperty("RANGE",sProperty); 00QJ596
Utility.log(sProperty); 05`"U#`:
lb-1z]YwQ
l?U=s7s0?
InputStream input = httpConnection.getInputStream(); bx8](cT_
//logResponseHead(httpConnection); 4VwF\
m0"K^p
TmQIpeych
byte[] b = new byte[1024]; pa[/6(
int nRead; ~P1~:AT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vA1YyaB
{ -)`_w^Ox
nStartPos += fileAccessI.write(b,0,nRead); 'BjTo*TB]Z
//if(nThreadID == 1) ,twx4r^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); esqmj#G
} @Nek;xJ
/*mF:40M;
<OMwi9
Utility.log("Thread " + nThreadID + " is over!"); "<!U
bDownOver = true; aixX/se
//nPos = fileAccessI.write (b,0,nRead); *9aJZWf>V
} $v|W2k
catch(Exception e){e.printStackTrace ();} ^Co$X+
} >X*tMhcb
} 7MKX`S
KUAzJ[>
TN2Ln?[xU
//打印回应的头信息 ?nd: :O
public void logResponseHead(HttpURLConnection con) hy5[ L`B
{ 4+RR`I8$Ge
for(int i=1;;i++) @%]A,\
{ 4I$Y(E}
String header=con.getHeaderFieldKey(i); u5(8k_7
if(header!=null) <xOX+D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -zR<m
Utility.log(header+" : "+con.getHeaderField(header)); +WH\,E
else x#>V50E
break; _v,0"_"
} ')y2W1
} ]:|B).
.,bpFcQ
;A*SuFbV
public void splitterStop() &|/_"*uM
{ L8VOiK=,
bStop = true; ?h= n5}Y
} v`HER6
nI\6aG?`
ju"z
} uzy5rA==
9P?0D
pM?;QG;jA
/* $Habhw
**FileAccess.java jx: IK
*//文件访问(定位，写) q<JCgO-F<
package NetFox; $TI^8 3
import java.io.*; i+Z)`
9L=mS
B*(]T|ff<
public class FileAccessI implements Serializable{ p)y5[HX
j/O~8o&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [FO4x`
RandomAccessFile oSavedFile; c|&3e84U
long nPos; u"[f\l
(%my:\>l
6Y9N=\`
public FileAccessI() throws IOException Kxr@!m"
{ x'GB#svi
this("",0); !+GYu;_
} T8XrmR&?PX
j/ 5
tn]nl!_@
public FileAccessI(String sName,long nPos) throws IOException U'fP
{ {q-&!l|
oSavedFile = new RandomAccessFile(sName,"rw"); J2bvHxb Rd
this.nPos = nPos; j#l=%H
oSavedFile.seek(nPos); t#k]K]
} z*\_+u~u
m=dNJF
!}(B=-
public synchronized int write(byte[] b,int nStart,int nLen) 9`tK9
{ G 3Z"U
int n = -1; !J$r|IX5
try{ FlqGexY5
oSavedFile.write(b,nStart,nLen); @!sK@&ow@%
n = nLen; d54iZ`
} @(t3<g
catch(IOException e) =+zDE0Qs
{ smP4KC"I(d
e.printStackTrace (); VmS_(bM
} |7qt/z
iQ'*QbP'Z
pRd.KY -<
return n; yPN'@{ 5#
} ,2@o`R.27
:Sq]|)
)GD7rsC`<
} &d_^k.%y
,"v&r(
cU1o$NRx
/* LP2~UVq
**SiteInfoBean.java +jm,nM9
*/ \TQZZ_Z
package NetFox; lSxb:$g
Br1R++]
T[oC='I+O
public class SiteInfoBean { u#0snw~)/
]}2)U
V;M_Y$`Lh
private String sSiteURL; //Site's URL BEdCA]T
private String sFilePath; //Saved File's Path O'<V[Y}6
private String sFileName; //Saved File's Name O)'CU1vMb
private int nSplitter; //Count of Splited Downloading File )(iv#;ByL
#N|\7(#~u
OF-k7g7
public SiteInfoBean() ~tDYo)hH8
{//nSplitter的缺省值为5 aJu&h2G
//default value of nSplitter is 5 @!8aZB3odt
this("","","",5); TEtmmp0OD
} 8q2a8I9g
mQ"~x]
HW@wia
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eg0_ <
{ iq#{*:1
sSiteURL= sURL; "+HJ/8Dd1
sFilePath = sPath; afm\Iv[*
sFileName = sName; LEb$Fd
this.nSplitter = nSpiltter; s,z~qL6&
19!?oeOU
PX:#+bq1
} ACszx\[K3
,06Sm]4L,
'Y38VOI%
public String getSSiteURL() ]C_+u_9
{ BU`X_Z1)
return sSiteURL; -f+#j=FX
} JcAsrtrG]
\J'}CX*aQ
kDmm
public void setSSiteURL(String value) R9XU7_3B
{ t{md&k4
sSiteURL = value; TW|K.t@5#H
} VkQ@c;C
[+ud7l
$8tk|uh
public String getSFilePath() D"7}&Ry:
{ 55Ss%$k@
return sFilePath; 9*qwXU_aV
} C6!F6Stn]g
s68(jYC7[
;mQj2Bwr
public void setSFilePath(String value) ?cU,%<r
{ d:kB Zrq
sFilePath = value; AwM`[`ReE
} `7"="T~ *
5pQpzn=
`fv5U%
public String getSFileName() fzsy<Vl",
{ 9"~ FKMN
return sFileName; Q,U0xGGz
} DAn2Pqf
\"lz,bT
I G1];vX
public void setSFileName(String value) V_7\VKR
{ P9v(5Z00|d
sFileName = value; }b_Ob
} #QNN;&L]R
AA\a#\#Z3
'l*X?ccKy
public int getNSplitter() H& |/|\8F
{ \ .xS
return nSplitter; v~$V
} U]PB)
!~#zd]0x;
pH'_k k
public void setNSplitter(int nCount) ^<I(
{ >pq~ &)^u
nSplitter = nCount; @16GF!.
} rN0<y4)!
} sJ6.3= c
F8pA)!AH
=uP? ?E
/* (bwD:G9
**Utility.java B[b>T=
*/ +kSu{Tc
package NetFox; (_FU3ZW!
O(^h_
rT2Njy1
public class Utility { xo>0j#
FnvpnU",
GJ9>i)+h;
public Utility() yD+4YD
{ C`5'5/-.
:i.@d?
L(y70T
} l=?e0d>O
(< +A w7
//线程睡眠 (Pc>D';{S
public static void sleep(int nSecond) Hw \of
{ $/wm k7T
try{ e]4$H.dP
Thread.sleep(nSecond); c'oiW)8;A
} $ XjijD9R
catch(Exception e) \n<! ld
{ VLuHuih
e.printStackTrace (); erH,EE^-x<
} bRAD_
} 4'QX1p
uw;Sfx,s
//日志 VF`!ks
public static void log(String sMsg) v,w af`)J
{ Giyh( DL
System.err.println(sMsg); {&5lZ<nu8A
} m8sd2&4
.}==p&(
>Hf{Mx{<
public static void log(int sMsg) \jfK']P/H
{ (/:m*x*6
System.err.println(sMsg); 'Lu<2=a~
} eiMP:
} *yBVZD|?H
%8*:VR
PaCCUF
/* DY2*B"^
**TestMethod.java /VYT](
*/ "&6vFmr
package NetFox; ~ZKJ:&f
eF+F"|1h
M7=,J;@
public class TestMethod { JduO^Fit
J"aw 1
ZHTi4JY
public TestMethod() 1T!o`*
{ ///xx/weblogic60b2_win.exe A \/~u"Y
try{ A@V$~&JCL5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g,,wG k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?fxM1<8
SiteFileFetch fileFetch = new SiteFileFetch(bean); g89@>?Mn
fileFetch.start(); H^d?(Svh
} l7-lXl"%q
catch(Exception e){e.printStackTrace ();} Tg{5%~L]
#/oH #/?
+ktv:d
} #W~jQ5NS\
DQ.4b
Qs1CK;+zU
public static void main(String[] args) Y 9$jJ1V
{ &%2^B[{
new TestMethod(); lHM+<Z
} p/Pus;*s
} 6 f*:;
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