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)); &<8Q/m]5
} F^& Rg
for(int i=0;i<nEndPos.length-1;i++) <X9 T}g
{ {.c(Sw}Eo
nEndPos = nStartPos[i+1]; |^&n\vXv
} <-KHy`u
nEndPos[nEndPos.length-1] = nFileLength; ,'[&" Eg
} Sj?u^L8es}
} `tZu~ n
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Us4J[MW<
//启动子线程 LB*qL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V mxVE=l
for(int i=0;i<nStartPos.length;i++) h!# (.P
{ wcGI2aflD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ).aQ}Gwx^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h_Ky2IB$
nStartPos,nEndPos,i); Uawf,57v<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3k)W0]:|<
fileSplitterFetch.start(); zO#{qF+~;
} 05eth
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q(@/,%EF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _-/aMfyQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yU*upQ
nEndPos = " + nFileLength); C'8v\C9Ag
// fileSplitterFetch[nPos.length-1].start(); Kjbt1n
eZDqW)x
="E^9!
//等待子线程结束 3I!xa*u
//int count = 0; cI}qMc
//是否结束while循环 W_k;jy_{9
boolean breakWhile = false; 4.]xK2sW
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m\a_0!K
while(!bStop) HU[a b
{ \~V ZY
write_nPos(); RiHOX&-7
Utility.sleep(500); 4dy2m!
breakWhile = true; a^yBtb~,P
|Z%I3-z_DS
Xk#"rM< Y
for(int i=0;i<nStartPos.length;i++) 7P3PQ%:
{ dD6I @N)X
if(!fileSplitterFetch.bDownOver) _isqk~ ul
{ TMt,\gTd
breakWhile = false; Nxk3uF^
break; zJ;K4)"j
} HQi57QB
} 97"dOi!Wh
if(breakWhile) =+um:*a.
break; gucd]VH
VAkZ@ u3'~
u`E24~
//count++; eL)* K>T
//if(count>4) BcJ]bIbKb
// siteStop(); vfID@g`!q+
} QuuR_Ao?c'
|ocIp/$
$HjKELoJ<
System.err.println("文件下载结束！"); ?Y6MC:l<
} CPRv"T;?
catch(Exception e){e.printStackTrace ();} ,:yv T6)p
} emZ^d/A
En@] xvE
1rhsmcE
//获得文件长度 /4 zO
public long getFileSize() j.C)KwelBS
{ *2MM
int nFileLength = -1; e&&;"^@-
try{ Q_}i8p'
URL url = new URL(siteInfoBean.getSSiteURL()); cG%ttfq\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eF8!}|*N
httpConnection.setRequestProperty("User-Agent","NetFox"); )9_jr(s
uQy5t:!
%9.] bd|%F
int responseCode=httpConnection.getResponseCode(); tCnx:1
if(responseCode>=400) h&|wqna
{ -w41Bvz0
processErrorCode(responseCode); o`^GUY}
return -2; //-2 represent access is error H^jFvAI,8
} (s?`*i:2
?h`Ned0P
] iKFEd
String sHeader; BKoc;20;
1FfdW>ay*
/m,0H)w1
for(int i=1;;i++) _!FM^N}|
{ TmS;ybsG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aQax85
//Utility.log(in.readLine()); p%304oP6
sHeader=httpConnection.getHeaderFieldKey(i); zGz^T
if(sHeader!=null) J"w!Q\_
{ ]h (TZu
if(sHeader.equals("Content-Length")) jRz2l`~7#
{ =~r?(u6d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p'afCX@J
break; 5ug?'TOj'
} Q(lj&!?1k
} |_l\.
else >V~q`htth
break; }g WSV
} &y1' J
} ?p{xt$<p
catch(IOException e){e.printStackTrace ();} \jn[kQ+pJ
catch(Exception e){e.printStackTrace ();} &fBLPF%6
%gd=d0vm
% '>S9Ja3
Utility.log(nFileLength); !O$*/7
7I;Give{
66\0JsT?3
return nFileLength; #8;|_RU
} {8M=[4_`l
s{q)m@
{ .KCK_ d
//保存下载信息（文件指针位置） 4)=LOGW
private void write_nPos() &]~z-0`$!
{ @+",f]
try{ `Rj<qz^7
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3j.Ft*SV
output.writeInt(nStartPos.length); Xu#\CYk
for(int i=0;i<nStartPos.length;i++) gF%lwq
{ ~p~8T
// output.writeLong(nPos); ]B>Y +
output.writeLong(fileSplitterFetch.nStartPos); b?-%Uzp<
output.writeLong(fileSplitterFetch.nEndPos); 5YIiO7@4
} s-r$%9o5
output.close(); &Pt|
} EWN$ILdD
catch(IOException e){e.printStackTrace ();} e,zR
catch(Exception e){e.printStackTrace ();} rtDm<aUh
} p}.P^`~j
8?W!U*0aS
k]x64hgm
//读取保存的下载信息（文件指针位置） ~BCSm]j
private void read_nPos() ~\hA-l36
{ k%QhF]
try{ @Z!leyam
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zQxZR}'
int nCount = input.readInt(); AO;`k]0e
nStartPos = new long[nCount]; +-,Q>`
nEndPos = new long[nCount]; 9>psQ0IRvr
for(int i=0;i<nStartPos.length;i++) 9QJ=?bIC#
{ b@N|sXt&C
nStartPos = input.readLong(); !-r@_tn|
nEndPos = input.readLong(); mLD0Lu_Ob3
} +3vK=d_Va
input.close(); ?[Q;275
} EF0{o_
catch(IOException e){e.printStackTrace ();} ) 0$7{3
catch(Exception e){e.printStackTrace ();} ,oDZ:";
} g'Ft5fQ"o/
}Evyfc#D
2uw%0r3Vi6
private void processErrorCode(int nErrorCode) _6qf>=qQ`"
{ %Ua*}C
System.err.println("Error Code : " + nErrorCode); p<'mc|hGq
} g=pz&cz;>\
-]5dD VSO
uW4G!Kw28
//停止文件下载 z>k6T4(
public void siteStop() H7"I+qE-G
{ 133lIX+(k
bStop = true; 5<4njo?k
for(int i=0;i<nStartPos.length;i++) N!;Y;<Ro_
fileSplitterFetch.splitterStop(); E?z 3&C
6fPuTQ}fY>
e`R*6^e
} .x6*9z#q
} %xLziF
//负责部分文件的抓取 +d\"n
**FileSplitterFetch.java ({![
*/ *we3i
package NetFox; =0,")aa!
Rjo6Pd{d<
Du$kDCU
import java.io.*; bEbO){Fe
import java.net.*; @Sub.z&T{
]*juF[r(
4_PMl6qo
public class FileSplitterFetch extends Thread { D8h?s
}<FBcc(n
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String sURL; //File URL D.qbzJz
long nStartPos; //File Snippet Start Position {_3ZKD(\
long nEndPos; //File Snippet End Position uVDB;6
int nThreadID; //Thread's ID 30FYq?
boolean bDownOver = false; //Downing is over lZ^XZjwoM
boolean bStop = false; //Stop identical 2K, 1wqf'
FileAccessI fileAccessI = null; //File Access interface [$.oyjd
nUmA
ErB6fl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {>QrI4*A
{ /RmLV
this.sURL = sURL; fLc<}DF
this.nStartPos = nStart; nT|fDD|
this.nEndPos = nEnd; JS&l h
nThreadID = id; S?hM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R9S7p)B
} 0g]ABzTn
lDp5aT;DsM
Fxv~;o#
public void run() @Z@yI2#e
{ !SiZA"
while(nStartPos < nEndPos && !bStop) <6p{eGAQV
{ rVQ:7\=Z
u9mMkzgSkP
sF_.9G)S0
try{ "TtK!>!.
URL url = new URL(sURL); yuFuYo&[?v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?ZlwRjB\
httpConnection.setRequestProperty("User-Agent","NetFox"); P;hjr;
String sProperty = "bytes="+nStartPos+"-"; 3m7$$N|
httpConnection.setRequestProperty("RANGE",sProperty); _sZ/tU@_-K
Utility.log(sProperty); F1Egcx/$V
t47 f$gq
uT]_pKm
InputStream input = httpConnection.getInputStream(); 5?9}^s4
//logResponseHead(httpConnection); Vl^jTX5N
5I T'u3V
[p4a\Qg0
byte[] b = new byte[1024]; }qV4]*+{
int nRead; o>U%3-+T^J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w^R5/#F_r
{ s_`wLQ7e
nStartPos += fileAccessI.write(b,0,nRead); 7jts;H=
//if(nThreadID == 1) An]*J|nFIY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W'gCFX
} 6EX:qp^`
cty~dzX^
9Od Kh\F (
Utility.log("Thread " + nThreadID + " is over!"); f=/S]o4/3
bDownOver = true; (nBJ,v)
//nPos = fileAccessI.write (b,0,nRead); IeN!nK-
} ?_<ZCH
catch(Exception e){e.printStackTrace ();} :Oq!.uO
} B TcxBh
} ~&B_ Bswf
j nI)n*
C6'[Tn
//打印回应的头信息 #"i}wS
public void logResponseHead(HttpURLConnection con) -fUz$Df/R
{ 0pkU1t~9
for(int i=1;;i++) Mv4JF(,S
{ Qt>yRt
String header=con.getHeaderFieldKey(i); dqF--)Nb
if(header!=null) 1f[!=p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;=h^"et
Utility.log(header+" : "+con.getHeaderField(header)); HLk}E*.mC
else iy$]9Wf6=@
break; P7u5Ykc*
} q%>L/KJ#
} !7%L%~z^
k(VA5upCs
aN;L5;m#>{
public void splitterStop() ZV;#ZXch
{ 7;|6g8=
bStop = true; #XJYkaL
} !xe<@$
C=PBF\RkKu
zKiKda%)
} {Qw,L;R
IUu[`\b=
qQpR gzw
/* $)7-wCl</
**FileAccess.java p(0!TCBs
*//文件访问(定位，写) (''`Ce
package NetFox; yRieGf1'SD
import java.io.*; B*D`KA
,C=Fgxw(
\n<N>j@3
public class FileAccessI implements Serializable{ IK%j+UB
H%faRUonz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uv_*E`pN~
RandomAccessFile oSavedFile; ~=0zZTG
long nPos; 4|++0=#D$
/5yWvra
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public FileAccessI() throws IOException zyCl`r[}
{ .4-;
this("",0); ;AG5WPI
} CH9#<?l
7qzI]
fep#Kb%"e
public FileAccessI(String sName,long nPos) throws IOException U8<GD|
{ &NGlkn
oSavedFile = new RandomAccessFile(sName,"rw"); @.CPZT
this.nPos = nPos; 5%4:)s{4|
oSavedFile.seek(nPos); =euoSH D}
} Sl 6}5
u[d8)+VX
]MB^0:F-
public synchronized int write(byte[] b,int nStart,int nLen) pazFVzT
{ y!aq}YS
int n = -1; ]Ff&zBJ
try{ WfO6Fvx%
oSavedFile.write(b,nStart,nLen); t~@TUTbx
n = nLen; .`,YUr$.
} %?RX}37K
catch(IOException e) 0kC!v,
{ Sm,%>
e.printStackTrace (); ,GR(y^S
} C=hE@
M:C*?;K:
@p`#y
return n; [ 8v)\lu
} -4hX-
/"/$1F%{
]@WJ&e/'@
} :5"|iRP'
im1]:kr7
I{1w8m4O6
/* g~Q#U;]
**SiteInfoBean.java pu`|HaQaE
*/ O[`n{Vl/
package NetFox; y f+/Kj< a
]Fjz+CGg
9"<)DS
public class SiteInfoBean { <'B`b
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tk, HvE
private String sSiteURL; //Site's URL 0Y"==g+>f
private String sFilePath; //Saved File's Path vEfX'gyk
private String sFileName; //Saved File's Name RHB>svT^K>
private int nSplitter; //Count of Splited Downloading File cQ+V4cW Z
WJJ!NoP
!_V*VD
public SiteInfoBean() ICV67(Ui
{//nSplitter的缺省值为5 ZC0F:=/K
//default value of nSplitter is 5 d~[>%&
this("","","",5); JQbI^ef_;
} m0\(a_0V
v3aiX
Vwv O@G7A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :.sK:W("v
{ t/q\Ne\\,
sSiteURL= sURL; }b,a*4pN
sFilePath = sPath; >xH3*0Lp
sFileName = sName; Grw_SVa^
this.nSplitter = nSpiltter; ;GE0iSC
L@[bgN`=v
+%>L;'L ^X
} ][_:{ N/
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public String getSSiteURL() ?|8H$1
{ :Eob"WH
return sSiteURL; 2Jj`7VH>
} N*o+m~:y
&O!d!Pf
u,'c:RMV
public void setSSiteURL(String value) flmcY7ZV
{ TYLf..i<
sSiteURL = value; orL7y&w(v:
} wBmbn=>#S
ExnszFX*
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public String getSFilePath() Wje7fv
{ l sUQ7%f
return sFilePath; ^&Qaf:M
} {O!fV<Vx 9
Cf%)W:Q9
oXz:zoNQ
public void setSFilePath(String value) =zbrXtp,
{ X|.X4fs
sFilePath = value; /+66y=`UJ
} BKJW\gS2
2U#OBvNU
@c.QrKSaD
public String getSFileName() Xv'64Nc!;
{ tc# rL
return sFileName; r4_ c~\jH
} ~%GUc ~
U>:p`@
w#"c5w~
public void setSFileName(String value) [%3{mAd
{ G.(9I~!
sFileName = value; i2swots
} h3JIiwv0!
r2H]n.MT
eJ?SLMLY
public int getNSplitter() 9]kWM]B)o
{ )DoY*'Cl
return nSplitter; /j.V0%
} ?{^T&<18t
."=Bx2
BfhOe~+i
public void setNSplitter(int nCount) Ak4iG2
{ tp0^%!*9
nSplitter = nCount; qKWkgackP
} {zg}KiNDZd
} \)LY_D:
iaPY>EP1
6idYz"P %
/* EV~_-YC
**Utility.java WlG/7$
*/ Zb}=?fcL;@
package NetFox; n1!u aUC
Yz{UP)TC
R=PjLH&)
public class Utility { y+X%qTB
AMtFOXx%I
33 N5>}
public Utility() {L.0jAwB
{ HW{+THNj
BeP0lZ
<4Ujk8Zj
} KqB(W,$
rsiG]o=8
//线程睡眠 Ee4oTU5Mb
public static void sleep(int nSecond) od-N7lp#
{ ~sk 4v:-
try{ ];(w8l
Thread.sleep(nSecond); 03{e[#6
} <tFq6|
catch(Exception e) A"w 1GBx
{ q \0>SG
e.printStackTrace (); Hh;7 hY\
} ucB<
} g3"`b)M
Y$%Ze]~
//日志 4xg%OH
public static void log(String sMsg) _.\p^ HM
{ j63w(Jv/
System.err.println(sMsg); <51(q_f
} V=1Y&y
^bS&[+9E
My=p>{s
public static void log(int sMsg) 3O$Q>.0w/
{ l$.C40v
System.err.println(sMsg); .PxtcC.K
} n802!d+Tn
} }JvyjE
/z~;.jRg
<BT}Tv9
/* #O`nQ
**TestMethod.java b+3{ bE
*/ P>jlFm
package NetFox; "TG}aS
ar>S_VW*
g6r3V.X'
public class TestMethod { 8'/vW~f
K]Ed-Tz8QZ
YHg4WW$
public TestMethod() C#vU'RNpl
{ ///xx/weblogic60b2_win.exe kg9ZSkJr
try{ |P~TZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XCQ=`3f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LLV:E{`p
SiteFileFetch fileFetch = new SiteFileFetch(bean); <C]s\"o-`
fileFetch.start(); -pyTzC$HO
} ~?S/0]?c
catch(Exception e){e.printStackTrace ();} i!sKL%z}
7e>n{rl
M%yT?R+
} :C>slxY
D0tI
1^Ci$ra
public static void main(String[] args) E3sl"d;~
{ X_O(j!h
new TestMethod(); &5c)qap;n
} WVp14Z?k
} Tig`4d-%
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