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)); X&C&DTB
} j("$qpv
for(int i=0;i<nEndPos.length-1;i++) vJZ0G:1
{ 8vQGpIa,
nEndPos = nStartPos[i+1]; \H<gKZquR
} @1+C*
nEndPos[nEndPos.length-1] = nFileLength; 8VG6~>ux'>
} ^n8ioL\*i
} +m?;,JGt
&\<!{Y<'
o95)-Wb
//启动子线程 =5:L#` .
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G!]%xFwYa
for(int i=0;i<nStartPos.length;i++) PJd7t%m;
{ Pdgn9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Oi#4|*b{W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]vj.s/F~
nStartPos,nEndPos,i); L1J \C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wQ1_Q8:Z
fileSplitterFetch.start(); 'Br:f_}
} y98v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s|er+-'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qHwHP 1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'ec G:B`S
nEndPos = " + nFileLength); (!b_o A8V
// fileSplitterFetch[nPos.length-1].start(); UI:YzR
w+A:]SU
Skb,cKU
//等待子线程结束 5L ]TV\\
//int count = 0; 8CXZ7p
//是否结束while循环 B$A`thQp
boolean breakWhile = false; R-7.q
` =ocr8c
(PVK|Q55y
while(!bStop) dA,irb I0W
{ 'Cki"4%<
write_nPos(); 8H2zMIB
Utility.sleep(500); N$'/J-^
breakWhile = true; !Cqm=q{K
z+@CzHCN
"n<rP 3y
for(int i=0;i<nStartPos.length;i++) GCrIaZ
{ D.7,xgH
if(!fileSplitterFetch.bDownOver) +SM&_b
{ rw CFt6;v
breakWhile = false; rbC4/9G\
break; !T+jb\O_
} cL+--$L
} 0QzUcr)3+
if(breakWhile) ywQ>T+
break; iJ8 5okv'
tKr.{#)
.`I;qF
//count++; \o|5/N
//if(count>4) _:RQ9x'
// siteStop(); eX{:&Do
} \zdY$3z
fGwRv%$^
{?!0<0
System.err.println("文件下载结束！"); y ~PW_,
} =6sA49~M
catch(Exception e){e.printStackTrace ();} :jKiHeBQu?
} Y=NXfTc
vp[;rDsIJ$
We8n20wf<
//获得文件长度 p{V_}:|=Q
public long getFileSize() eU*0;#
{ <FkoWN
int nFileLength = -1; ?Z1&ju,Hd-
try{ <n+]\a97*
URL url = new URL(siteInfoBean.getSSiteURL()); XEUy,>mR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ORc20NFy7
httpConnection.setRequestProperty("User-Agent","NetFox"); 1"hd5a
0\y{/P?I$
.uoQ@3
int responseCode=httpConnection.getResponseCode(); kPuI'EPK
if(responseCode>=400) &'mq).I2
{ >u-6,[(5X*
processErrorCode(responseCode); doX8Tq
return -2; //-2 represent access is error hoLQuh%2%
} Uo~-^w}
#GlQwk3
fr19C%{
String sHeader; q^I/
id"-eMwp
|_} LMkU)
for(int i=1;;i++) (C&Lpt_
{ NDqvt$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~{xm(p
//Utility.log(in.readLine()); <'N(`.&3C
sHeader=httpConnection.getHeaderFieldKey(i); H}p5qW.tH:
if(sHeader!=null) k$NNpv&;d
{ fqY;>Z
if(sHeader.equals("Content-Length")) )5j1;A:gr
{ jG E=7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y$Y*%D^w
break; 7gx 7NDt
} 7<Yf
} } vzNh_
else A><q-`bw
break; qb[UA5S\`
} G9YfJ?I
} YWK|AT-4
catch(IOException e){e.printStackTrace ();} w y\0o
catch(Exception e){e.printStackTrace ();} yPmo@aw]1
cU[^[;4J<
C@ns`Eh8w
Utility.log(nFileLength); ElK7jWJ+
kgl7l?|O
LT2UY*
return nFileLength; dln1JZ!
} )<+t#5"
)UoF*vC(
:p|wo"=@Ge
//保存下载信息（文件指针位置） vTk\6o q
private void write_nPos() Bokpvd-c7
{ 2|re4
try{ bgNN0,+8
output = new DataOutputStream(new FileOutputStream(tmpFile)); h@H8oZ[
output.writeInt(nStartPos.length); s-[v[w'E
for(int i=0;i<nStartPos.length;i++) )/vse5EG+
{ e%wzcn
// output.writeLong(nPos); CBrC
output.writeLong(fileSplitterFetch.nStartPos); R2`-*PZ_
output.writeLong(fileSplitterFetch.nEndPos); _=Eb:n+X
} dJ|/.J$d
output.close(); zcrM3`Zh
} _s%;GWj
catch(IOException e){e.printStackTrace ();} n]Z() "D
catch(Exception e){e.printStackTrace ();} "pa2,-&
} Gp.XTz#=
8rEUZk
N0POyd/rL
//读取保存的下载信息（文件指针位置） ,jc')#]9B
private void read_nPos() ^8q(_#w`K
{ 9ZVzIv(
try{ a^5.gfzA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %={[e`,
int nCount = input.readInt(); DKnlbl1^?
nStartPos = new long[nCount]; N\nxo0sl
nEndPos = new long[nCount]; nPRv.h
for(int i=0;i<nStartPos.length;i++) U-6pia/o
{ 3X>x`
nStartPos = input.readLong(); W3E7y?
nEndPos = input.readLong(); (/;<K$u*h
} $eU oFa5A
input.close(); nb|KIW
} Py^fWQ5I~%
catch(IOException e){e.printStackTrace ();} Iss)7I
catch(Exception e){e.printStackTrace ();} e{6I-5`|,#
} &WV&_z
S"Z.M _
g=)OcTd#
private void processErrorCode(int nErrorCode) ;QS(`SK l
{ <oKoz0!
System.err.println("Error Code : " + nErrorCode); 1{Kv
} /JGET
z?M_Cz;:J
`"s*'P398
//停止文件下载 G5!J9@Yi
public void siteStop() [yn\O=%5
{ 3IyNnm=u
bStop = true; Bbj%RF2,
for(int i=0;i<nStartPos.length;i++) c_ Dg0
fileSplitterFetch.splitterStop(); uWjSqyb:
}v4T&/vt-
(`)ZR%i
} $_Kcm"oj
} */)O8`}2
//负责部分文件的抓取 =pnMV"'9
**FileSplitterFetch.java Y9r##r+
*/ nAT,y9&
package NetFox; VBq|j"o0"
k%Wj+\93f
,ui=Wi1
import java.io.*; 1a]QNl_x
import java.net.*; p6AF16*f0
EGw;IFj)
R|'ftFebB.
public class FileSplitterFetch extends Thread { wmDO^}>ZP
+[B@83
,TlYQ/j%h
String sURL; //File URL 5MHcgzyp
long nStartPos; //File Snippet Start Position E@/*eJ
long nEndPos; //File Snippet End Position 4'#?"I
int nThreadID; //Thread's ID Y_= ]w1
boolean bDownOver = false; //Downing is over wB+X@AA
boolean bStop = false; //Stop identical :um]a70
FileAccessI fileAccessI = null; //File Access interface 1)t*l;.
CNl @8&R
z2U^z*n{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,!vI@>nhG
{ {v}BtZ
this.sURL = sURL; (Tv~$\=
this.nStartPos = nStart; TOw;P:-
this.nEndPos = nEnd; ,lDOo+eE%:
nThreadID = id; =:*2t
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *X\J[$!
} b_w(F_0
@MKf$O4K
HlOn=>)<
public void run() ?+G /5,e
{ '1"vwXJ"
while(nStartPos < nEndPos && !bStop) dZ|x `bIgs
{ Q" G;L
j@.^3:
O39f
try{ .~,=?aq^
URL url = new URL(sURL); ']U<R=5T$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V*gh"gZ<
httpConnection.setRequestProperty("User-Agent","NetFox"); SNc$!
String sProperty = "bytes="+nStartPos+"-"; $1Qcz,4B|
httpConnection.setRequestProperty("RANGE",sProperty); }v6@yU
Utility.log(sProperty); @tlWyUju
|ITh2m
Ejj+%)n.
InputStream input = httpConnection.getInputStream(); s"~3.J
//logResponseHead(httpConnection); -"6Z@8=
#|/+znJm
r2m&z%N&
byte[] b = new byte[1024]; 6t4Khiwx
int nRead; e.WKf,e"X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .u:aX$t+
{ CU@}{}Yl
nStartPos += fileAccessI.write(b,0,nRead); @?*; -]#)
//if(nThreadID == 1) SBg|V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kD}vK+
} jI%glO'2
^s\T<;
YySo%\d
Utility.log("Thread " + nThreadID + " is over!"); '"T9y=9]s
bDownOver = true; *p0Kw>
//nPos = fileAccessI.write (b,0,nRead); Sym}#F\s
} ]]P@*4!
catch(Exception e){e.printStackTrace ();} 4"veqrC
} ` <u2 N
} @H$Sv
1E=E ?$9sg
kS4YxtvB
//打印回应的头信息 sGx3O i
public void logResponseHead(HttpURLConnection con) VIg6'
{ aU*}.{<!
for(int i=1;;i++) P=.~LZZ]89
{ B.:1fT7lI
String header=con.getHeaderFieldKey(i); 3mhjwgP<nn
if(header!=null) SqZ .}s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :eIQF7-
Utility.log(header+" : "+con.getHeaderField(header)); v.hQ9#:
else xlH3t&i7
break; 5\}E4y
} $\q.Zb
} e,MgR\F}
kH`?^^_yJ
x[xRqC vL
public void splitterStop() 4s@Tn>%SP
{ 5?[hr5E.E
bStop = true; >+DMTV[O
} WF:4p]0~)
V9jxmu F,
%/ "yt}"|
} Q\>mg*79
FY`t7_Y?GV
+X`&VO6~
/* R{ udV
**FileAccess.java Tv6y+l
*//文件访问(定位，写) 9bhubx\^/
package NetFox; (\o4 c0UzK
import java.io.*; *Q#oV}D_
q]Kv.x]$R
w OOu/Y
public class FileAccessI implements Serializable{ UyFC\vQ
+d7Arg!m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aKE`nA0\B
RandomAccessFile oSavedFile; `"hWbmQ
long nPos; ydA@@C\&
97~>gFU77#
B&_Z&H=
public FileAccessI() throws IOException I0qJr2[X~
{ I1rB,%p
this("",0); ;&'ryYrex
} .FV^hrJxI;
9dm<(I}
}Q@~_3,UJ
public FileAccessI(String sName,long nPos) throws IOException ^;F5ymb3U
{ Xvoz4'Gme
oSavedFile = new RandomAccessFile(sName,"rw"); 1Wiz0X/
this.nPos = nPos; wS+!>Q_]w
oSavedFile.seek(nPos); b- bvkPN
} 5SZa,+]
'IT]VRObP
W;l0GxOxQ
public synchronized int write(byte[] b,int nStart,int nLen) qHtIjtt[q
{ Z}t^i^u
int n = -1; 0Lb{HLT
try{ TD%L`Gk
oSavedFile.write(b,nStart,nLen); ,LP^v'[V7
n = nLen; \Rb:t}
} &,=FPlTC=
catch(IOException e) I>##iiKN
{ 7\[fjCg\w
e.printStackTrace (); a2ho+TwT
} $rTb'8
8Lgm50bs
7=5eLc^
return n; QleVW
} z@w}+fYO
JZ~wacDd
Yi)s=Q:
} 3~V.
Lis>Qr
13w(Tf
/* 4T;<`{]
**SiteInfoBean.java HTz`$9
*/ 0 x' d^
package NetFox; d0C _:_
U]w"T{;@.)
KV$4}{
public class SiteInfoBean { t1"#L_<e
Zd%wX<hU"
V"'PA-z3
private String sSiteURL; //Site's URL pPag@L
private String sFilePath; //Saved File's Path E/*&'Osq
private String sFileName; //Saved File's Name (x?Tjyzw
private int nSplitter; //Count of Splited Downloading File 9thG4T8
psc Fb$b
i;s;:{cn
public SiteInfoBean() HyOrAv <
{//nSplitter的缺省值为5 Jj\lF*B
//default value of nSplitter is 5 awvP;F?q|
this("","","",5); @6UZC-M0
} 8D,*_p
&"I csxG
2%6 >)|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R dwt4A+
{ ^jUw4Dj~-q
sSiteURL= sURL; PgGUs4[
sFilePath = sPath; %''L7o.#a
sFileName = sName; mo] l_'
this.nSplitter = nSpiltter; EApbaS}Up
5ya^k{`+ZO
vp.?$(L^@/
} 4#7*B yvf
QIlZZ
OG$v"Yf~
public String getSSiteURL() @\XeRx;
{ Ie(.T2K
return sSiteURL; _MLf58
} "om7 :d
3)6-S
FMI1[|:;
public void setSSiteURL(String value) lw[c+F7
{ FKu8R%9xn%
sSiteURL = value; o|xZ?#^h
} dFDf/tH
6}e*!,2Xj
pr7lm5
public String getSFilePath() qP<D9k>
{ SY[3O
return sFilePath; 3X11Gl
} XD|g G
|:JT+a1
&KAe+~aPm
public void setSFilePath(String value) ZV+tHgzlv5
{ :v;U7
sFilePath = value; ~IjID
} _p+E(i 9
5Gy#$'kdf
"t(_r@qU/
public String getSFileName() RR ^7/-
{ DyiJ4m}kh
return sFileName; `o295eiY(b
} la_c:#ho
C!Srv7
\3^ue0
public void setSFileName(String value) 1ONkmVtL
{ gCC7L(1
sFileName = value; t(-,mw
} zU+q03l8Ur
0 }od Q#
_`&l46
public int getNSplitter() n+hL/aQ+
{ 0V(}Zj>
return nSplitter; Zx_^P:rL
} "O<ETHd0
2~?E'
PWiUW{7z
public void setNSplitter(int nCount) L*[3rqER
{ Yg3nT:K_Y&
nSplitter = nCount; W_JO~P
} y^`JWs,
} ?SElJ?Z
`HkNO@N[
3u$1W@T(
/* CssE8p>"F
**Utility.java J:glJ'4E
*/ ,r;xH}tbi
package NetFox; 6{HCF-cQd
u"*DI=pwb
Wu/#}Bw#
public class Utility { l[ $bn!_e
& rab,I"
1VlU'qY
public Utility() fM4B.45j
{ I*3}erT
y"q>}5
_7<{+Zzm
} jxkjPf?
s{yw1:
//线程睡眠 %}VH5s9\
public static void sleep(int nSecond) 3S7"P$q
{ z77>W}d
try{ }0Ns&6)xG
Thread.sleep(nSecond); aYb97}kI
} ?V^7`3F
catch(Exception e) qz>R"pj0g
{ GgG#]a!_f
e.printStackTrace (); ()l3X.t,$
} +lqGf
} ji1vLu4|t
C$1W+(
//日志 ]>VG}e~b
public static void log(String sMsg) >- \bLr
{ r.\L@Y<
System.err.println(sMsg); K8&;B)VT>
} % (y{Sca
Bso#+v5
A,cXN1V
public static void log(int sMsg) qGV_oa74
{ j/d}B_2
System.err.println(sMsg); y]fI7nu&
} gE#'Zv{7
} KZw~Ch}b9
ggx_h
\xCCJWek
/* h&$h<zL[
**TestMethod.java yEI@^8]s
*/ ezp%8IZ;
package NetFox; ^0OP&s;"
lbBWOx/|
}Ze*/p-
public class TestMethod { LD}~]
]$[sfPKA
"a8E0b
public TestMethod() nOGTeKjEJ
{ ///xx/weblogic60b2_win.exe jRS{7rx%MH
try{ WI/tWj0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !ka* rd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3uqhYT;
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ww2@!ng
fileFetch.start(); _xp8*2~-
} Mz(Vf1pi%
catch(Exception e){e.printStackTrace ();} ?1SsF>|
+y?Ilkk;j
Z,.Hz\y1D
} WR"D7{>tw
YOD.y!.zq7
TQF+aP8[L
public static void main(String[] args) \:WWrY8&
{ qJrT
new TestMethod(); c>B1cR
} :x*)o+
} T`ibulp
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