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)); ]fC7%"nB
} ][t6VA
for(int i=0;i<nEndPos.length-1;i++) $8@+j[>
{ W5I=X]&
nEndPos = nStartPos[i+1]; \`gEu{
} mJ$Htyr
nEndPos[nEndPos.length-1] = nFileLength; CB]l[hM$
} T*\$<-^
} :#SNpn=@
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hVZo"XUb
//启动子线程 ^ LbGH<#J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ohplj`X[21
for(int i=0;i<nStartPos.length;i++) z8tl0gd%D
{ 7TdQRB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0||F`24
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b,Lw7MY}[
nStartPos,nEndPos,i); kW(Kh0x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k<Oy%+C
fileSplitterFetch.start(); %M6 c0d[9-
} C8MWIX}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _n_sfT6)B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |."G?*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I61%H9;
nEndPos = " + nFileLength); ;^ov~PPl
// fileSplitterFetch[nPos.length-1].start(); >13/h]3
Hf_'32e3<
0etwz3NuW
//等待子线程结束 -t>Z 9
//int count = 0; M8_R
//是否结束while循环 G"C;A`6
boolean breakWhile = false; .qinR6=
9A<0zt
mt^`1ekoY
while(!bStop) InN{^uN
{ cD8Ea(
write_nPos(); @T/qd>T o
Utility.sleep(500); P57GqT
breakWhile = true; m9Il\PoTq
-p^'XL*Z
?OO%5PSen
for(int i=0;i<nStartPos.length;i++) ^Po,(iIn
{ -%=RFgU4
if(!fileSplitterFetch.bDownOver) N"~ qoJO
{ b-uZ"Kf^
breakWhile = false; 0V7 _n
break; ~4+8p9f
} p}BGw:=
} -xTKdm D
if(breakWhile) f| =# q
break; Z+,CL/
gi 5XP]z
g@(4ujOT
//count++; ZR6&AiL(Bj
//if(count>4) %HVD^. V
// siteStop(); 22'vm~2E
} &L'6KEahR
6Wb!J>93
_[%n ~6
System.err.println("文件下载结束！"); nUqL\(UuY
} ]Y=S
catch(Exception e){e.printStackTrace ();} ]7l{g9?ZtV
} (QKsB3X
{RJ52Gx(
}v&K~!*
//获得文件长度 ( mt*y]p?
public long getFileSize() `OBl:e
{ g+3Hwtl
int nFileLength = -1; |C4o zl=O?
try{ F#KF6)P
URL url = new URL(siteInfoBean.getSSiteURL()); [brkx3h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UT~4Cfb
httpConnection.setRequestProperty("User-Agent","NetFox"); q55M8B 4w
\eT/%$
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int responseCode=httpConnection.getResponseCode(); I<KCt2:X
if(responseCode>=400) ovSH}h!
{ "G@E6{/
processErrorCode(responseCode); Y=|CPE%V
return -2; //-2 represent access is error /wlFD,+8
} I[%M!_+
ILNXaJ'0a
5E0wn'
String sHeader; )Z&HuEg{ZR
'?b\F~$8
<a fO 6?`
for(int i=1;;i++) &AJUY()8
{ oo\IS\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Gj*SPU
//Utility.log(in.readLine()); yduuFK
sHeader=httpConnection.getHeaderFieldKey(i); wZ O@J|
if(sHeader!=null) ^t7_3%%w
{ oLd:3,p}
if(sHeader.equals("Content-Length")) X= SG
{ 8M~u_`6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CxkMhd8qz
break; nqrDT1b**
} T"IW Jpc
} 1B(G]o_>!
else zv,\@Z9.($
break; /RMer Xj
} PQi }Evxa
} 5e)i!;7Uv
catch(IOException e){e.printStackTrace ();} >r~|1kQ.
catch(Exception e){e.printStackTrace ();} y=wdR|b
E~}[+X@
|Cu1uwy
Utility.log(nFileLength); !*9FKDB{
yZ?$8r
y]w )`}Ax
return nFileLength; r<v_CFJ
} $Q=$?>4U
x~%\y
?S8$5gA
//保存下载信息（文件指针位置） =I7[L{+~Y
private void write_nPos() TX&[;jsj
{ ~6] )*y
try{ =?^-P{:\?
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,Io0ZE>`V
output.writeInt(nStartPos.length); Kjv2J;Xuh
for(int i=0;i<nStartPos.length;i++) [@x
{ t&38@p
// output.writeLong(nPos); V@Ax}<$A
output.writeLong(fileSplitterFetch.nStartPos); @kS|Jz$iY
output.writeLong(fileSplitterFetch.nEndPos); w~ijD ^g
} 2UQN*_
output.close(); ,=yOek}
} W%=Zdm rv
catch(IOException e){e.printStackTrace ();} "--/v. Cs
catch(Exception e){e.printStackTrace ();} d4Ixuux<3
} S3nB:$_-;
I.UjST
C"k2<IE
//读取保存的下载信息（文件指针位置） ~0av3G
private void read_nPos() BF>T*Z-Ki
{ g~eJ YS,
try{ %s]U@Ku(a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dP?nP(l
int nCount = input.readInt(); nMLU-C!t
nStartPos = new long[nCount]; Sb^add0dT
nEndPos = new long[nCount]; `Yg7,{A\J
for(int i=0;i<nStartPos.length;i++) \MF3CK@/
{ RzMA\r;#
nStartPos = input.readLong(); X #&(~1O
nEndPos = input.readLong(); w 7Cne%J8
} eog\pMv
input.close(); CZF^Wxk
} 7?+5%7-
catch(IOException e){e.printStackTrace ();} ^tQPJ
catch(Exception e){e.printStackTrace ();} 0kkRK*fp}x
} '9f6ZAnYpQ
/5&3WG&<u
E*Pz <
private void processErrorCode(int nErrorCode) | pF5`dX
{ 7k.d|<mRv
System.err.println("Error Code : " + nErrorCode); +Kxe ymwr2
} &t[z
N'htcC
f34_?F<h
//停止文件下载 ?f(pQy@V
public void siteStop() ~JIywzcf8
{ bXa %EMF
bStop = true; =PI^X\if88
for(int i=0;i<nStartPos.length;i++) >hHJ:5y
fileSplitterFetch.splitterStop(); 3| GNi~
,w,ENU0~f
^qE<yn
} xhw8#
} cdd P T
//负责部分文件的抓取 K(%dcUGDK>
**FileSplitterFetch.java 5cPSv?x^F@
*/ 0f_66`
package NetFox; NEjPU#@c
:(5]Z^
er&uC4Y]a
import java.io.*; JsZAP
import java.net.*; %@M00~-
AGw1Pl8]K
!%SdTaC{T
public class FileSplitterFetch extends Thread { )6O\WB|
%i;r]z-
{JCSR2BB
String sURL; //File URL v!WU |=u
long nStartPos; //File Snippet Start Position M!;`(_2
long nEndPos; //File Snippet End Position W;xW: -
int nThreadID; //Thread's ID SSl8
boolean bDownOver = false; //Downing is over "`gfy
boolean bStop = false; //Stop identical )$2%&9b
FileAccessI fileAccessI = null; //File Access interface ]#vvlM>/
2+c>O%L
M Ak-=?t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .=.yZ
{ {hkM*:U
this.sURL = sURL; s!8J.hD'I
this.nStartPos = nStart; W}#QKZ)MB
this.nEndPos = nEnd; M="WUe_
nThreadID = id; > gA %MT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )R [@G.
} q/W{PBb-2k
hP'~
\'\N"g`Fr
public void run() sR7{i
{ l8hvq(,{
while(nStartPos < nEndPos && !bStop) rCnV5Yb0O
{ d/ 'A\"o+
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7Va#{Y;Zy
try{ n?<# {$
URL url = new URL(sURL); a'*5PaXU@/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l<0[ K(
httpConnection.setRequestProperty("User-Agent","NetFox"); C,sD?PcSi+
String sProperty = "bytes="+nStartPos+"-"; 2n-Tpay0
httpConnection.setRequestProperty("RANGE",sProperty); ,H#qgnp
Utility.log(sProperty); SK2J`*
F^%{ ;
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InputStream input = httpConnection.getInputStream(); `? 9]'
//logResponseHead(httpConnection); Z9;nC zHm
qd#(`%_/
]yj4~_&O
byte[] b = new byte[1024]; #Tgz,e9
int nRead; )7Hon
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "NXm\`8
{ hJ$C%1;
nStartPos += fileAccessI.write(b,0,nRead); E :'
//if(nThreadID == 1) Q G=-LXv:@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,q'gG`M N
} eMpEFY
g%fJyk'
B $ y44
Utility.log("Thread " + nThreadID + " is over!"); R:pBbA7E
bDownOver = true; qH{8n`
//nPos = fileAccessI.write (b,0,nRead); -Y 6.?z
} 8JjU 9#
catch(Exception e){e.printStackTrace ();} Oo3qiw
} _.Z&<.lJ
} <'o'H
%z!d4J75
{"gyXDE1
//打印回应的头信息 Xn ZX *Y]"
public void logResponseHead(HttpURLConnection con) 4$q)e<-
{ _x,-d|9bd
for(int i=1;;i++) }]n>A
{ -Fok%iQ'5
String header=con.getHeaderFieldKey(i); , $D&WH
if(header!=null) BRSgB-Rr7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XEgx#F ;F
Utility.log(header+" : "+con.getHeaderField(header)); uV/HNzC
else 2RSHBo
break; 1"4nmw}
} P"~qio-
} _($-dJ{
yuy+}]uB@
\KnD"0KW
public void splitterStop() %Zv(gI`A
{ I 1VEm?CQ
bStop = true; ?-.Ep0/
} TYJnQ2m
Ls$g-k%c@Q
&[W3e3Asra
} *k@0:a(>
qqz,~EhC
`1[Sv"
/* sJHy=z0m
**FileAccess.java wk@(CKQzI,
*//文件访问(定位，写) H[_uVv;}6
package NetFox; kj<D4)
import java.io.*; x>8}|ou
\{+nXn
!rsqr32]
public class FileAccessI implements Serializable{ hklO:,`
nX.sh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W:+2We@
RandomAccessFile oSavedFile; ` HE:D2b
long nPos; vElL.<..
W_f"Gk
4-}A'fTU8
public FileAccessI() throws IOException utm+\/
{ !+|N<`
this("",0); (-Ct!aW|
} L9unhx
9^ *ZH1
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public FileAccessI(String sName,long nPos) throws IOException 5S-o 2a
{ SFk11
oSavedFile = new RandomAccessFile(sName,"rw"); `9Q,=D+
this.nPos = nPos; \Zz= 4 j
oSavedFile.seek(nPos); 8a$jO+UvN
} {GH`V}Ob
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i37a}.;
public synchronized int write(byte[] b,int nStart,int nLen) ]stLC; nI
{ %6c*dy
int n = -1; W|-N>,G
try{ )r6SGlE[Y
oSavedFile.write(b,nStart,nLen); {, *Y
n = nLen; 4k&O-70y4^
} !Bd* L~D
catch(IOException e) CXP $bt}
{ Cp~3Jm3
e.printStackTrace (); IIt^e#s&
} (.XDf3
b\|p
"/K&qj
return n; w<F;&';@h
} )zLS,/pk^
U37?P7i's
hC 4X Y
} tU2toV
8|-mzb&
t1{%FJ0F
/* Qpv}N*v^
**SiteInfoBean.java f$S QhK5`
*/ +8vzkfr3It
package NetFox; W.6JnYLQ&
>~wk
3f2Hjk7,d
public class SiteInfoBean { }vxH)U6$q
(h>X:!
sr($Bw
private String sSiteURL; //Site's URL gc8PA_bFz
private String sFilePath; //Saved File's Path ]gZ8b- 2O
private String sFileName; //Saved File's Name DEwtP
private int nSplitter; //Count of Splited Downloading File -.Pu5et4
WoWM
T#_n-b>
public SiteInfoBean() DGfQo5#
{//nSplitter的缺省值为5 ,ZP3F+XKb
//default value of nSplitter is 5 O\8|niW|
this("","","",5); I&NpN~AU
} !%\To(r[
rs<&x(=Hv
\gzwsT2&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rd1ku=
{ hy&Hl
sSiteURL= sURL; z9kX`M+
sFilePath = sPath; <%#y^_
sFileName = sName; q~dg
this.nSplitter = nSpiltter; @G$<6CG\
3;l>x/amk
#M9D" <pn}
} #m$%S%s
K,,@',
,JBw$C
public String getSSiteURL() Am?Hkh2
{ 8OtUY}R
return sSiteURL; WT!\X["FI$
} |%cO"d^ri
O2/w:zOg'
aE cg_es
public void setSSiteURL(String value) g*c\'~f;
{ i7FR78^
sSiteURL = value; ._8cJf.ae
} = SJF\Z
%iS]+Sa.K
(*WZsfk>/<
public String getSFilePath() wukos5
{ ?G>TaTiK#
return sFilePath; #bZ=R
} JTB~nd>
+e4<z%1
CU`Oc>;*T
public void setSFilePath(String value) u`Qcw|R+
{ Vh2/Ls5
sFilePath = value; yz$1qEII`q
} HN~4-6[q
Aag)c~D
2hC$"Dfp
public String getSFileName() ,p`bWm
{ R}6la.mQ
return sFileName; Tocdh.H|
} n_&)VF#n(
%s :
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public void setSFileName(String value) W#_gvW
{ 4NR5?s
sFileName = value; 2xdJ(\JWM
} P:-/3
7Z~szD
:h^UC~[h 3
public int getNSplitter() ts\>_/
{ S,9WMti4x
return nSplitter; `&[:!U2]F
} YJvT p~
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f#Cdx"
public void setNSplitter(int nCount) <\>ak7m
{ 1nTaKK q
nSplitter = nCount; p}|wO&4h
} G/3lX^Z>
} =}GyI_br;8
sH,)e'0
{ZEXlNPww
/* Dlf=N$BL7d
**Utility.java 5 ^J8<s@_
*/ ZV4' |q
package NetFox; 2OlC7X{
{!Z_&i5
K}3"KC
public class Utility { t}+c/ C%b=
xWb?i6)z&
by<@Zwtf
public Utility() .LcE^y[V
{ '<D}5u72
78~V/L;@S2
PxD}j 2Kd
} 9QZwUQ
&0Zk3D4
//线程睡眠 rWpfAE)!
public static void sleep(int nSecond) ~EkGG .
{ QGG(I7{-
try{ `3P62M<
Thread.sleep(nSecond); afq +;Sh
} 6-}e-H
catch(Exception e) G6mM6(Sr
{ V="f)'S$
e.printStackTrace (); Riuv@i^6K
} E?D{/k,zZ
} ibUPd."W
`|?$; )
//日志 vbh#[,lh
public static void log(String sMsg) {:OVBX
{ r9*H-V$
System.err.println(sMsg); S%#Mu|
} ,8?*U]}
P,=J"%a-
*]?YvY
public static void log(int sMsg) ]=<@G.[=
{ Yx c >+mx
System.err.println(sMsg); ^@"f%3
} * xXc$T
} %t.IxMY
9gayu<J
7B"aFnK;[J
/* _tJURk%
**TestMethod.java ]r5Xp#q2
*/ Q 5TyS8
package NetFox; RVy87_J1
PP|xIAc
a :AcCd)
public class TestMethod { o|E(_Y4d
me\)JCZpb{
I@v.Hqg+7
public TestMethod() !gQ(1u|r
{ ///xx/weblogic60b2_win.exe hmk5 1
try{ :Xr3 3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~,1X>N"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cu|q&
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'Q,<_L"
fileFetch.start(); 8Wp1L0$B
} CMUphS-KE
catch(Exception e){e.printStackTrace ();} `&JA7UD>
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lR^Qm|
} 6 VDF@V$E
zxHfQ(
s#49pDN
public static void main(String[] args) PmTd+Gj$
{ -W vAmi
new TestMethod(); !\v3bOi&
} ,aL"Wy(
} v9kzMxs,
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