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)); |:qaF
} Tt^PiaS!
for(int i=0;i<nEndPos.length-1;i++) /NE<?t N
{ gc5u@(P"
nEndPos = nStartPos[i+1]; 3)D'Yx
} o`tOnwt
nEndPos[nEndPos.length-1] = nFileLength; I`e$U
} aC!e#(q
} BH`%3Mw
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<H; z4
//启动子线程 b\{34z,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mBAI";L3
for(int i=0;i<nStartPos.length;i++) aL)}S%5o?
{ [nSlkl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mZ%"""X\Ei
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4O I''i
nStartPos,nEndPos,i); v@xbur\L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `Zdeq.R]
fileSplitterFetch.start(); 2YW|/o4
} Re[x$rw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), So6ZNh9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b\Wlpb=QZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j<*
nEndPos = " + nFileLength); a9f!f %9
// fileSplitterFetch[nPos.length-1].start(); AiF'*!1
,Wbr; zb
'R-Ly^:Qd
//等待子线程结束 UrC>n
//int count = 0; N}|<P[LW
//是否结束while循环 iY~.U`b`
boolean breakWhile = false; NA :_yA"
\zx &5a #
~]w|ULNa3|
while(!bStop) _ ^2\/@
{ bUcEQGHcZ=
write_nPos(); bU3P;a(
Utility.sleep(500); ;nSOeAF)Q
breakWhile = true; . X:
]J '#KT{
%pJRu-D
for(int i=0;i<nStartPos.length;i++) vk1E!T9X
{ SlaHhq3
if(!fileSplitterFetch.bDownOver) pYRqV
{ d*B^pDf
breakWhile = false; *UerLpf
break; >b1#dEY
} a1Kh
} ',_E;(
if(breakWhile) Tr6J+hS
break; }CM</
$~;h}I
-J6G=+s/
//count++; 1H-d<G0)
//if(count>4) n)<S5P?
// siteStop(); ELvP<Ny}
} LvPcH
w;OvZo|
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System.err.println("文件下载结束！"); |T;]%<O3E
} Au\j6mB
catch(Exception e){e.printStackTrace ();} =xs"<Q*w>
} RE<s$B$[
:>q*#vlb
S|K#lL
//获得文件长度 2{Johqf
public long getFileSize() }x~1w:zHd
{ Lw1aG;5
int nFileLength = -1; wCitQ0?
try{ NZQl#ZJH:
URL url = new URL(siteInfoBean.getSSiteURL()); 2zPO3xL,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =i1+t"=
httpConnection.setRequestProperty("User-Agent","NetFox"); a5dc#f Kf
RxB9c(s^@
C$x r)_
int responseCode=httpConnection.getResponseCode(); $[6]Ly(F)
if(responseCode>=400) J$>9UCk7B
{ k|r|*|8
processErrorCode(responseCode); /QW-#K|S&
return -2; //-2 represent access is error 9j8<Fs0M
} q}+Fm?B
=jWjUkm2
0|chRX
String sHeader; }od5kK;
' X9D(?O
%>z)Q
for(int i=1;;i++) lh]Q\
{ hMNC]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JBK(Nk
//Utility.log(in.readLine()); C[JGt9{Y
sHeader=httpConnection.getHeaderFieldKey(i); }~O`(mnD}K
if(sHeader!=null) \2^_v' >K
{ ;%<R>gDWv
if(sHeader.equals("Content-Length")) R^f-j-$o]
{ \1MMz Z4rf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0_f6Qrcj
break; DQ`\HY
} j&|>Aa${
} 3$n O@rOS
else aWk1D.
break; *p.70,5,
} JW2~ G!@
} INF}~DN]
catch(IOException e){e.printStackTrace ();} _qp^+
catch(Exception e){e.printStackTrace ();} VSDG_:!K
+d289"
,&ld:v?~
Utility.log(nFileLength); gNaB^IY
8r\;8all
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return nFileLength; 7H$wpn Zln
} +\s&v!
cKe{ ]a
d+L!s7
//保存下载信息（文件指针位置） QT)5-Jy
private void write_nPos() EHlkt,h*
{ W&s@2y?rF
try{ LQ{z}Ay
output = new DataOutputStream(new FileOutputStream(tmpFile)); qgkC)
output.writeInt(nStartPos.length); g+pj1ycw/
for(int i=0;i<nStartPos.length;i++) ,b'QL6>`
{ )2&y;{]
// output.writeLong(nPos); %|o2d&i
output.writeLong(fileSplitterFetch.nStartPos); ~&%&Z
output.writeLong(fileSplitterFetch.nEndPos); )Rj,PF-9Z[
} O <#H5/Tq
output.close(); 8h$f6JE
} 7blo<|9
catch(IOException e){e.printStackTrace ();} &Ndq^!e
catch(Exception e){e.printStackTrace ();} d3&l!DoX
} kNC]q,ljt5
Z9p`78kYyh
*Hed^[sO
//读取保存的下载信息（文件指针位置） Rdj/n :
private void read_nPos() oaGpqjBGQ
{ qu+Zl1~$]
try{ LQDU8[-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S&z8-D=8k
int nCount = input.readInt(); i}e4P>ADD
nStartPos = new long[nCount]; sA:k8aj
nEndPos = new long[nCount]; `Qxdb1>mjY
for(int i=0;i<nStartPos.length;i++) .?dYY;P
{ XM:Y(#?l
nStartPos = input.readLong(); qGhwbg
nEndPos = input.readLong(); ]s>y se
} <d] t{M62W
input.close(); m-AW}1:\f
} Cp!Qd e
catch(IOException e){e.printStackTrace ();} 4&}dA^F
catch(Exception e){e.printStackTrace ();} ZB'ms[
} S*Hv2sl
"jA?s9
$(N+E,XB
private void processErrorCode(int nErrorCode) wdLlQD
{ cIB[D.
System.err.println("Error Code : " + nErrorCode); <-s5 ;xwtS
} D]*<J"/]d
8iXt8XY3
$e/[!3CASP
//停止文件下载 kx6-8j3gD7
public void siteStop() t<H@c9{;*
{ DEN (pA\
bStop = true; _d*QA{
for(int i=0;i<nStartPos.length;i++) f6U i~
fileSplitterFetch.splitterStop(); aF5=k:k
vI5'npM
Tp&7CNl|
} tXW7G@
} !v?WyGbUg
//负责部分文件的抓取 |0s)aV|K
**FileSplitterFetch.java Xb\de_8!
*/ [l:}#5\]4
package NetFox; n"|1A..^
vfpK|=[7o
du_TiI
import java.io.*; WEsX+okj
import java.net.*; w)Wg 8
?8TIPz J
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public class FileSplitterFetch extends Thread { f;cY&GC
c7f11N!v>b
U#' WP
String sURL; //File URL 0;n}{26a
long nStartPos; //File Snippet Start Position "S^""5
long nEndPos; //File Snippet End Position g$9EI\a
int nThreadID; //Thread's ID %Z!3[.%F
boolean bDownOver = false; //Downing is over Vm]u-R`{
boolean bStop = false; //Stop identical -0:Equ?pz
FileAccessI fileAccessI = null; //File Access interface a@s@E
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D{G~7P\.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zA%$l&QN]
{ "fZWAGDBO\
this.sURL = sURL; &KPJB"0L
this.nStartPos = nStart; o8!uvl}:9
this.nEndPos = nEnd; WwAvR5jq
nThreadID = id; ^rssZQKY[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,!Q^"aOT:
} j@C*kj;-
]mdO3P
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public void run() D'Y=}I)8Dn
{ xG~7kj3
while(nStartPos < nEndPos && !bStop) &p_V<\(%
{ Ew>lk9La(
$4u8"ne)
=+"=|cQ
try{ K3-Cuku
URL url = new URL(sURL); 8XhGo2zf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y_}jf,b4
httpConnection.setRequestProperty("User-Agent","NetFox"); <MzXTy3\
String sProperty = "bytes="+nStartPos+"-"; oa2v/P1`
httpConnection.setRequestProperty("RANGE",sProperty); Pt[ b;}
Utility.log(sProperty); C{2y*sx
hB??~>i3
p$_X\,F
InputStream input = httpConnection.getInputStream(); t;L7H E@Y
//logResponseHead(httpConnection); EU4j'1!&g<
.g52p+Z#
]JvZ{fA%*
byte[] b = new byte[1024]; *Y<1KXFU
int nRead; _>4Qh#6K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @zi_@B
{ HsRQiai*
nStartPos += fileAccessI.write(b,0,nRead); &09g0K66
//if(nThreadID == 1) !lk9U^wnd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,*j@Zb_r
} Q5>]f/LD
=x5k5NIF
6y
Utility.log("Thread " + nThreadID + " is over!"); a n,$Z,G#K
bDownOver = true; _&}z+(Ug
//nPos = fileAccessI.write (b,0,nRead); IW5N^J
} d6+{^v$#
catch(Exception e){e.printStackTrace ();} 5~\GAjf
} %W,V~kb
} {bMOT*X=A
:,1kSM%r
^zVW 3Y q
//打印回应的头信息 >v1ajI>O&{
public void logResponseHead(HttpURLConnection con) idSc#n22
{ IfzZ\x .
for(int i=1;;i++) -cs$E2 -
{ D,&o=EU
String header=con.getHeaderFieldKey(i); Zg/ ],/`
if(header!=null) t>%+[7?6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xay~fD
Utility.log(header+" : "+con.getHeaderField(header)); Ae|bAyAK
else j,CVkA*DY
break; ^Kfm(E
} 7]lUPLsl
} *!&,)''
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Rs;Y|W4'
public void splitterStop() -Ta| qQa
{ "d c- !
bStop = true; pu,|_N[xq8
} uL9O_a;!
b_>x;5k
)A=&3Ui)ab
} M:d} P
=v49[i
MKZq*
/* >o|.0aw<
**FileAccess.java B> V)6\
*//文件访问(定位，写) w*krPaT3
package NetFox; N`rz>6,k1
import java.io.*; 6<{XwmM
S9lT4
7Kn}KO!Y8
public class FileAccessI implements Serializable{ 2b^E8+r9
">x"BP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JE ''Th}
RandomAccessFile oSavedFile; ^+rI=c 0
long nPos; S- JD}+9
#?klVK&e/
yLEAbd%+
public FileAccessI() throws IOException ~R C\
{ )bl^:C
this("",0); "eZ~]m}L0
} UB3hC`N\
\CVrLn;}
G}#p4\/
public FileAccessI(String sName,long nPos) throws IOException :[!b";pR
{ ]Ia}H+&
oSavedFile = new RandomAccessFile(sName,"rw"); C1po]Ott*
this.nPos = nPos; [J +5
oSavedFile.seek(nPos); p}(pIoyUF
} fO,m_ OR:)
3%YDsd vQx
cNiNLwc
public synchronized int write(byte[] b,int nStart,int nLen) [,Fu2j]
{ Ob@HzXH
int n = -1; n7(/ml+Q_
try{ ?#Y1E~N
oSavedFile.write(b,nStart,nLen); JV@b(x`
n = nLen; QW= X#yrDO
} p"d_+
catch(IOException e) dlCmSCp%
{ `{ ` W-C
e.printStackTrace (); |)+45e
} Fr)6<9%xVm
^|ul3_'?
W #V`|JA
return n; CM4#Nn=i~
} - sL4tMP
!;E{D
Hl=M{)q@
} p61F@=EL
@f`s%o
iG+=whvL
/* H/$oGhvl
**SiteInfoBean.java '.IR|~Y
*/ ASULg{
package NetFox; V~]&1
^EcwY- Qr
5;X3{$y
public class SiteInfoBean { qv)%)n
g [c^7
{"mb)zr
private String sSiteURL; //Site's URL >N-l2?rE
private String sFilePath; //Saved File's Path ".sRi
private String sFileName; //Saved File's Name A O3MlK9t
private int nSplitter; //Count of Splited Downloading File 36\_Y?zx%
}T&~DVM
MTAq}8
public SiteInfoBean() DTz)qHd#X
{//nSplitter的缺省值为5 i^}ib RQbN
//default value of nSplitter is 5 "Zu>cbE
this("","","",5); F&$~]R=&
} /TY=ig1z
xbD]EC
g]jCR*]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g<^-[w4/
{ ->`R[k
sSiteURL= sURL; ];*?`}#
sFilePath = sPath; UAOH9*9*
sFileName = sName; h7J4 p
this.nSplitter = nSpiltter; U?A3>
HiSNEp$-4$
.05x=28n%
} <b_?[%(u
lt& c/xi_
`2,F!kCt
public String getSSiteURL() ,L-G-V+
{ GU7f27p
return sSiteURL; ca,U>'(y
} S3gd'Bahq
_bSn YhS
nHl{'|~
public void setSSiteURL(String value) |[X-i["y
{ X1o=rT
sSiteURL = value; 1ZO/R%[
} {~EPP .
|vgYi
<`d;>r=4z
public String getSFilePath() 4q*mEV
{ 5U6b\jxX
return sFilePath; Zqj EVVB
} /7igPNhx
:I8HRkp
[U_
public void setSFilePath(String value) 8y'.H21:;
{ C=&;4In
sFilePath = value; K(rWM>Jv
} '1rO&F
XPT@ LM
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public String getSFileName() =DwY-Ex
{ }Apn.DYbbf
return sFileName; F.-:4m(Z
} r=S,/N(1
g)nT]+&
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public void setSFileName(String value) ,D2nUk
{ U U@
sFileName = value; b)7v-1N
} (W5JVk_o
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*{dMo,.eI
public int getNSplitter() C=`MzZbJ
{ t(p}0}Pp
return nSplitter; V z-]H]MW,
} [}`-KpV!;
> *soc!#Y
[Nu py,v
public void setNSplitter(int nCount) nJY3 1(p
{ l`."rei%)
nSplitter = nCount; F[*/D/y(
} S#nW )=
} B!((N{4H+
"mc ]^O
Or:P*l
/* mq+<2 S
**Utility.java 0}N"L ml
*/ sf8F h
package NetFox; IGF25-7B
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public class Utility { _ qU-@Y$
^y[- e9O|
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public Utility() gjn1ha"h%.
{ ^J)0i_RS
aole`PD,l
m^>v~Q~~
} Pxf/*z
Suy +XHV
//线程睡眠 RKy!=#;17
public static void sleep(int nSecond) y#i` i
{ 75;g|+
try{ Nf%/)Tk
Thread.sleep(nSecond); Xo3@-D_c!c
} &/(JIWc1su
catch(Exception e) X<&Y5\%F
{ 3,1HD_
e.printStackTrace (); r0q?e`nsA
} OM81$Xo=
} iH8V]%
RaOLy \
//日志 ~L:H]_8F l
public static void log(String sMsg) =s&ycc;-5}
{ F8|m i`f-
System.err.println(sMsg); 2yV^'o)
} P4fnBH4OQ
mI5!rrRD|
PxA OKUpI
public static void log(int sMsg) +#9 4X)*
{ E_\V^
System.err.println(sMsg); w9675D+
} V/BU(`~i
} }WHq?
iw{^nSD
Bo8NY!
/* ef2)k4)"
**TestMethod.java eIQ@){lJ-]
*/ eU\XAN#@
package NetFox; gv,1 CK
u>/Jb+
+0)H~ qB\
public class TestMethod { 9ePom'1f1
77-G*PI*I
A45!hhf
public TestMethod() k|^`0~E
{ ///xx/weblogic60b2_win.exe 5]K2to)>`
try{ !\!j?z=O8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hGRHuJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b-RuUfUn0
SiteFileFetch fileFetch = new SiteFileFetch(bean); I8Y #l'z
fileFetch.start(); a3L-q>h
} a}X.ewg
catch(Exception e){e.printStackTrace ();} t\-|J SZ
D9!$H!T _
?hYWxWW
} J3$@: S'
bu{dT8g'U
V=<AI.Z:w
public static void main(String[] args) g]E3+:5dk
{ F |aLF{
new TestMethod(); gv1y%(`|n(
} FM7`q7d
} /!fJ`pu!
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