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)); 1{%EQhNd
} _VR Sdr5
for(int i=0;i<nEndPos.length-1;i++) A^JeB<, 5a
{ | zj$p~
nEndPos = nStartPos[i+1]; ' %OQd?MhL
} QzIK580%t
nEndPos[nEndPos.length-1] = nFileLength; e+=Ojo#
} g?M\Z";
} /40Z-'Bl=(
nD.4c-hd$q
g!7/iKj:
//启动子线程 (^eSm]<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PDX^MYoN
for(int i=0;i<nStartPos.length;i++) 7I`e5\ u
{ N40.GL0s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'oHtg @
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r,i^-jv;
nStartPos,nEndPos,i); c\.4I4uy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <!&nyuSz
fileSplitterFetch.start(); XN]kNJX
} IQdiVj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &oYX093di
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m$A|Sx&sG$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^MUtmzh
nEndPos = " + nFileLength); hkv&Od,
// fileSplitterFetch[nPos.length-1].start(); suaTXKjyk+
G F,/<R#
"sf8~P9qy
//等待子线程结束 A;w,m{9<
//int count = 0; L]kSj$A
//是否结束while循环 F)lDK.
boolean breakWhile = false; V?HC\F-
\x)T_]Gcm
+WK!}xZR
while(!bStop) 2@1A,
{ ar=uDb;
write_nPos(); xc8MOm
Utility.sleep(500); I8`@Srw8
breakWhile = true; e0+N1kY
\8=>l?P
+Ld4e]
for(int i=0;i<nStartPos.length;i++) +l2{EiQw
{ D^I%tn=F
if(!fileSplitterFetch.bDownOver) %Ox*?l _
{ 6N:fq
breakWhile = false; M2[;b+W9
break; 7 \!t/<
} 2ME3=C
} U=QV^I Qm
if(breakWhile) QW|,_u5j
break; V3xC"maA@
|OUr=b
W7S`+Pq
//count++; 41^+T<+
//if(count>4) ((N<2G)
// siteStop(); 6^s=25>p
} vR3'B3y
{2}O\A
cc*A/lD
System.err.println("文件下载结束！"); ; ob>$ _
} S j)&!
catch(Exception e){e.printStackTrace ();} #Fl"#g$
} AwAUm 2^
t`o-HWfS.
{l%Of
//获得文件长度 vtKQvQ
public long getFileSize() {PnvQ?|Z
{ e]'ui<`
int nFileLength = -1; 0g,;Yzm
try{ !0CC&8C`
URL url = new URL(siteInfoBean.getSSiteURL()); !=3[Bm G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZO5_n
httpConnection.setRequestProperty("User-Agent","NetFox"); ?"N,do
<[@AMdS
s%2w&Us*
int responseCode=httpConnection.getResponseCode(); 4`yCvPu
if(responseCode>=400) IC{\iwO/~c
{ 7;jwKA;k
processErrorCode(responseCode); *8M0h9S$
return -2; //-2 represent access is error X9K@mX
} szu!*wc9
uPr'by
zt/b S/
String sHeader; WUm83"
eY)ugq>'
yl/-!
for(int i=1;;i++) @e8b'w3
{ <^c?M[j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Uoe;4ni
//Utility.log(in.readLine()); !K-lO{Z^
sHeader=httpConnection.getHeaderFieldKey(i); C#d.3t
if(sHeader!=null) 18f!k
{ h+<vWo}H
if(sHeader.equals("Content-Length")) 8/F}vfKEN
{ IL;JdIa
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S {oW
break; 2$?bLvk
} <E/4/ ANN
} y.(Yh1
else v._Q XcE
break; M3P\1
} 3tzb@T
} Q#w mS&$f
catch(IOException e){e.printStackTrace ();} ySAkj-< /P
catch(Exception e){e.printStackTrace ();} r@b M3V_o
qWX%[i%
;,2i1m0"
Utility.log(nFileLength); N^</:R
2[!#Xf
tljZE)
return nFileLength; $cjwY$6
} cq:<,Ke
(mbC! !>
=h5&:?X
//保存下载信息（文件指针位置） `o/G0~T)
private void write_nPos() O&BNhuW2
{ .)=T1^[hI
try{ dpG l
output = new DataOutputStream(new FileOutputStream(tmpFile)); %87D(h!.I4
output.writeInt(nStartPos.length); WXHvUiFf
for(int i=0;i<nStartPos.length;i++) ?.Iau/
{ DBTeV-G9~R
// output.writeLong(nPos); UU\wP(f
output.writeLong(fileSplitterFetch.nStartPos); %!DdjC&5*
output.writeLong(fileSplitterFetch.nEndPos); V /i~IG`h/
} pHKcKqB*13
output.close(); (sM$=M<$
} C_> WU
catch(IOException e){e.printStackTrace ();} rtM29~c>@
catch(Exception e){e.printStackTrace ();} pQ~Y7
} zXX=WH
^.3(o{g
78M%[7Cq<i
//读取保存的下载信息（文件指针位置） LV}Z[\?
private void read_nPos() i ZU1w7Z
{ 2/o_,k
try{ xWRkg$A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D[jPz0
int nCount = input.readInt(); I{nrOb1G(
nStartPos = new long[nCount]; g\.O5H9Od
nEndPos = new long[nCount]; OQnb^fabY
for(int i=0;i<nStartPos.length;i++) &VPfI
{ ZNfQM&<d
nStartPos = input.readLong(); 7a0T]
nEndPos = input.readLong(); t[e`wj+qz
} cG)U01/"
input.close(); G/ sRiwL
} y':JUwUN
catch(IOException e){e.printStackTrace ();} m>FP&~2
catch(Exception e){e.printStackTrace ();} u> @@
} @@W-]SR
dBm!`;r4
\yhj{QS.k
private void processErrorCode(int nErrorCode) @1vpkB~ w
{ 9jI5bi)
System.err.println("Error Code : " + nErrorCode); $O^"OQ_@
} 3S"kw
|.?$:D&6
y:YJv x6&4
//停止文件下载 `u" )*Q}
public void siteStop() x31Jl{x8\?
{ 06NW2A%wv
bStop = true; wBz5_ OFVw
for(int i=0;i<nStartPos.length;i++) JN-W`2
fileSplitterFetch.splitterStop(); =`g@6S
]$)U~)T iW
]--" K{
} mvu$
} AP9>_0=
//负责部分文件的抓取 ldWrv7.P
**FileSplitterFetch.java _F`RwBOjs
*/ 9'0v]ar
package NetFox; vw*,_f
ebiOR1)sN
,&LGAa
import java.io.*; ki?ETC
import java.net.*; %I#[k4,N
ozkmZ;
_ykT(`.#
public class FileSplitterFetch extends Thread { 5@^['S4%8*
J3y4D}
qa,i:T(w
String sURL; //File URL IzlmcP3
long nStartPos; //File Snippet Start Position Vi>`g{\
long nEndPos; //File Snippet End Position <xh";seL
int nThreadID; //Thread's ID /-Y.A<ieN8
boolean bDownOver = false; //Downing is over <|;)iT1VeT
boolean bStop = false; //Stop identical %Krf,H
FileAccessI fileAccessI = null; //File Access interface O~c\+~5M*
Qq<+QL|
h 6juX'V
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (3N;-
{ Y\j5{;V
this.sURL = sURL; QBLha']'%
this.nStartPos = nStart; lj 2OOU{
this.nEndPos = nEnd; Jj7he(!_1
nThreadID = id; ]]50c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -op(26:W<
} oT*qMLdn
I5#zo,9
:ywm4)
public void run() a[7Lqu
{ 1{?5/F \ +
while(nStartPos < nEndPos && !bStop) iJ p E`
{ d[y(u<Vl
4_d'Uh&]
frUO+
try{ oNp(GQ@0
URL url = new URL(sURL); '<Jqp7$dL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HBcL1wfS
httpConnection.setRequestProperty("User-Agent","NetFox"); AZfW
String sProperty = "bytes="+nStartPos+"-"; ?K= X[
httpConnection.setRequestProperty("RANGE",sProperty); !c;BOCqa
Utility.log(sProperty); ,7ZV;f81
yc.9CTxx
&'oZ]}^0
InputStream input = httpConnection.getInputStream(); /7uAf{
//logResponseHead(httpConnection); %)sG 34
-HUlB|Q8r
0tEe $9eK@
byte[] b = new byte[1024]; 0%"sOth
int nRead; eY8rm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tl^![Z
{ {R}Kt;L:Ut
nStartPos += fileAccessI.write(b,0,nRead); |6GDIoZ
//if(nThreadID == 1) Hg2Rcl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Bp5^(s
} O^KIB%}fu
D\k'Eez
UpS7>c7s
Utility.log("Thread " + nThreadID + " is over!"); rvp#[RAaS}
bDownOver = true; s|IC;C|
//nPos = fileAccessI.write (b,0,nRead); 6Ej.X)~'K
} C(}N*e1
catch(Exception e){e.printStackTrace ();} y-lBaTE9
} ##BfI`FJ
} \&b1%Asyz
?V' zG&n@
` *q>E
//打印回应的头信息 @k3xk1*
public void logResponseHead(HttpURLConnection con) uO5y{O2W
{ `]j:''K
for(int i=1;;i++) `XrF ,
{ 2JL\1=k;
String header=con.getHeaderFieldKey(i); n 'E:uXv"
if(header!=null) fzjAP7 y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m*~Iu<5L
Utility.log(header+" : "+con.getHeaderField(header)); Eh&-b6:
else v`Yj)
break; SYwB #|
} R?iC"s!
} #H.DnW
"-R19SpJKh
Mq52B_
public void splitterStop() N;R I A
{ 1h#e-Oyff
bStop = true; odhcU5
} ,*CPG$L
<g1=jG:7k
'f-8P
} GS+Z(,J>=
8 DPn5E#M1
%gEgpJd
/* GUC.t7!
**FileAccess.java |syvtS{
*//文件访问(定位，写) Cq[<CPAS
package NetFox; Zmz $ hr
import java.io.*; _&e$?hY
6h?)x
98XlcI#
public class FileAccessI implements Serializable{ 7mA:~-.u
odKdpa Zc[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T\w{&3ONm
RandomAccessFile oSavedFile; /a}` y
long nPos; <+_WMSf;4
;k (M4?
}///k]_Sh
public FileAccessI() throws IOException t&Jrchk
{ th%T(D5n
this("",0); a/xnf<(H
} z[WdJN{
zg$NrI&
=@!s[
public FileAccessI(String sName,long nPos) throws IOException 65l9dM2
{ MG vp6/Pd
oSavedFile = new RandomAccessFile(sName,"rw"); a+<{!+3v
this.nPos = nPos; oAgU rl;R
oSavedFile.seek(nPos); LwcAF g|
} BHt9$$Z|
}aL&3[>>
)u1=, D
public synchronized int write(byte[] b,int nStart,int nLen) B^Hhrz!
{ (} wMU]!_
int n = -1; 7{p6&xXx
try{ \G2PK&)F
oSavedFile.write(b,nStart,nLen); APyH.]mQ
n = nLen; 2}rYH;Mx
} }pKKNZ`[
catch(IOException e) dg#w!etB
{ eC`G0.op
e.printStackTrace (); :"gu=u!
} Pr3>}4M
NUh+ &M
P52qtN<
return n; 0~BZh%s< (
} T@d4NF#
vf-8DB
}(!3)k7*
} ?@QcKQ@
uOPLJ?%
''}2JJU{
/* kV4,45r
**SiteInfoBean.java [y"Yi PK
*/ 0(Hzh?t_
package NetFox; g/gaPc*86
*fI\|%K
$V;0z~&!'
public class SiteInfoBean { 5ljEh -
Esf\Bo"
aX? tnDv
private String sSiteURL; //Site's URL W!JEl|]
private String sFilePath; //Saved File's Path /|@~:5R5H
private String sFileName; //Saved File's Name ;&XC*R+
private int nSplitter; //Count of Splited Downloading File VyWzb
's$/-AV
NG?g(
public SiteInfoBean() m}'!W`<
{//nSplitter的缺省值为5 *mn"GK6
//default value of nSplitter is 5 @4$la'XSx
this("","","",5); 0P;\ :-&p
} TPmb]j
,%U\@*6=
=oTj3+7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) " :V@AT
{ X?Or.
sSiteURL= sURL; Jt3*(+J>/
sFilePath = sPath; B^C5?
sFileName = sName; K+`deH_d
this.nSplitter = nSpiltter; XV1XzG#C
J:G{
BOv^L?)*Z
} ptlag&Z
pW_mS|
G)&!f)6
public String getSSiteURL() 0@RVM|
{ 3e1%G#fu
return sSiteURL; 9[h8Dy
} UTqKL*p523
n>xuef
`t+;[G>ZE
public void setSSiteURL(String value) fJ+4H4K
{ =.qPjp_Qd
sSiteURL = value; 0@&/W-VXg
} q siV
<DhuY/o
j9.%(*
public String getSFilePath() l@`n4U.Gwl
{ ps*iE=D
return sFilePath; 2Hk21y\
} rdH^"(
|}@teN^J*U
$g\p)- aU
public void setSFilePath(String value) JY%l1:}G3
{ f6m h_l
sFilePath = value; s\(@f4p
} fONycXM]
&:~9'-O
CKX3t:HP0
public String getSFileName() yF-`f _
{ %&wi@ *#
return sFileName; Rb0{W]opt+
} $|VdGRZ1
xPJ@!ks9
rr2^sQ;_
public void setSFileName(String value) uEkGo5
{ ;8cTy8
sFileName = value; DIgur}q)@
} Th4}$)yrkN
h]}DMVV]
A2.4#Qb'
public int getNSplitter() w8F`RRHEE
{ kJ)Z{hy
return nSplitter; @ ZN@EOM$+
} r+tHVh
fIn^a3TV
M2nUY`%#v
public void setNSplitter(int nCount) <slrzc_>&
{ c`oW-K{
nSplitter = nCount; N w/it*f
} u.}H)wt
} 8&CQx*
\T?6TDZ]
:g{ybTSEe
/* !PgwFJ
**Utility.java 9[[$5t`8
*/ H% FP!03
package NetFox; FLIU}doc
FJFO0Hb6
|{MXDx
public class Utility { 2rHQ7
H!|g?"C
Xm<|m#
public Utility() Lzx2An@R
{ B/Ltb^a
HrUE?Sq
CD4@0Z+
} *hh9 K
,x?Jrcx~'C
//线程睡眠 #VsS C1
public static void sleep(int nSecond) z6|kEc"{
{ d+"F(R9
try{ AqHGBH0
Thread.sleep(nSecond); qRq4PQ@
} -J0I2D
catch(Exception e) dJ>tM'G
{ "#pN
e.printStackTrace (); ?P}) Qa
} nN>Uh T
} `W7;-
dvglh?7d
//日志 p*JP='p
public static void log(String sMsg) zLPCWP.u
{ I/gfsyfA
System.err.println(sMsg); $?9u;+jIR
} Ifq|MZ\
j`_Z`eG
5Gz~,_
public static void log(int sMsg) )-1$y+s>
{ |=W>4>
System.err.println(sMsg); 9QkssI
} yKmHTjX=
} 5oOs.(m|*C
la_
lxBcO/
/* @;[.#hK
**TestMethod.java }(WUZ^L
*/ N8!e(YK_
package NetFox; UaHN*@
]agdVr^
"T}HH
public class TestMethod { >_X(rar0
(unJwh{7Q
$:?=A5ttuo
public TestMethod() o/!a7>xO4
{ ///xx/weblogic60b2_win.exe `2'*E\
try{ 2 xi@5;!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L)Da1<O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wh^I|D?"
SiteFileFetch fileFetch = new SiteFileFetch(bean); d"+ _`d=`
fileFetch.start(); @!(V0-
} lPz5.(5'
catch(Exception e){e.printStackTrace ();} g$8aB{)
be.Kx< I
,qhv(
} X<H+Z2d
u#Uc6? E
-AKbXkc~\
public static void main(String[] args) 1$"wN z
{ `y.i(~^1
new TestMethod(); TJs@V>,
} tNW0 C]
} ;fv/s]X86I
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