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)); >Wg= Tuef
} yCX5 5:
for(int i=0;i<nEndPos.length-1;i++) ?y>N&\pt2
{ Iil2R}1
nEndPos = nStartPos[i+1]; @uSO~.7
} d[9,J?'OQ
nEndPos[nEndPos.length-1] = nFileLength; ktu?-?#0,
} '.}}k!#
} B`pBIUu
GT>'|~e
?7\V)$00(&
//启动子线程 w+$$uz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OM'iJB6=
for(int i=0;i<nStartPos.length;i++) W 4{ T<
{ T2{e1 =Z7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UBo0c?,4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IPot][ N>
nStartPos,nEndPos,i); B=Hd:P|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *i#2>=)
fileSplitterFetch.start(); ;_sJ>.=\
} %$BRQ-O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yoE-a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {uDW<u_!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =D zrM%
nEndPos = " + nFileLength); a%go[_w
// fileSplitterFetch[nPos.length-1].start(); 2"0VXtv6
4+olyBht
L3]J8oEmU
//等待子线程结束 !~^2Mu(X
//int count = 0; gx\V)8Zr
//是否结束while循环 =lNW1J\SW
boolean breakWhile = false; jAQ{H
bR`5g
:?f<tNU$
while(!bStop) ui]iOp
{ 01Jav~WR
write_nPos(); 6v@Prw@.b
Utility.sleep(500); C&O8fNB_
breakWhile = true; f,YORJ
]t[%.^5#
A-x^JC=
for(int i=0;i<nStartPos.length;i++) eI-fH
{ g5BL"Dn
if(!fileSplitterFetch.bDownOver) )\U:e:Zae
{ qw+7.h#V
breakWhile = false; e]<Syrk
break; wXNng(M7
} DLwlA!z
} fb f&bJT
if(breakWhile) |dIR v
break; :GvC#2p
e.\>GwM
w+m7jn!$
//count++; EXdX%T\
//if(count>4) s:<y\1Ay
// siteStop(); BDt$s( \
} (~|)Gmq2
NbWEP\dS'z
nS#F*)
System.err.println("文件下载结束！"); x]VycS
} +5fB?0D;
catch(Exception e){e.printStackTrace ();} ~#gc{C@
} lG6&uMvo
_d!sSyk`
y9}qB:[bR
//获得文件长度 [w](x
public long getFileSize() *gmc6xY
{ {UH45#Ua
int nFileLength = -1; sta/i?n
try{ :M6|V_Yp
URL url = new URL(siteInfoBean.getSSiteURL()); yCz"~c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =u0=)\0@r
httpConnection.setRequestProperty("User-Agent","NetFox"); `&I6=,YLp
,WdSJ BK'a
=Vh]{y~$
int responseCode=httpConnection.getResponseCode(); JKKp5~_~
if(responseCode>=400) A._CCou
{ ]:ca=&>
processErrorCode(responseCode); 52^3N>X4X
return -2; //-2 represent access is error ?Gf'G{^}
} ,T;sWl
!/`AM<`o
@3eMvbI
String sHeader; qY&(O`?m&
Sw$&E
.}E<,T
for(int i=1;;i++) #WA7}tHb
{ D}%VZA}].
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [YQtX_;w
//Utility.log(in.readLine()); -X*.scw
sHeader=httpConnection.getHeaderFieldKey(i); "-fyX!
if(sHeader!=null) %AV3eqghCg
{ z}.!q{Q
if(sHeader.equals("Content-Length")) >hoIJZP,
{ "Ol;0>$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H$KE*Wwq
break; )&1yt4 x6%
} aO.'(kk8
} &JAQ:([:
else fU@}]&
break; >C+0LF`U
} 0(|R NV_
} GC66n1- X
catch(IOException e){e.printStackTrace ();} ^%~ztn 51
catch(Exception e){e.printStackTrace ();} cE 8vSQ%
$;>,
9<kKno
Utility.log(nFileLength); n} GIf&
pWSYbN+d
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return nFileLength; E87/B%R
} EAF<PMb
v|VY5vN
jPPaL]
//保存下载信息（文件指针位置） -le:0NUwI
private void write_nPos() po*s
{ `=uCp^+v
try{ v!t*Ng
output = new DataOutputStream(new FileOutputStream(tmpFile)); *D~@xypy
output.writeInt(nStartPos.length); uQ&&?j
for(int i=0;i<nStartPos.length;i++) &|%z!x6f
{ tH5f;mY,
// output.writeLong(nPos); + h`:qB
output.writeLong(fileSplitterFetch.nStartPos); :|<D(YA
output.writeLong(fileSplitterFetch.nEndPos); ]O<Yr'
} vMzR3@4e
output.close(); NTXT0:
} s.1(- "DU
catch(IOException e){e.printStackTrace ();} q]<Xx{_
catch(Exception e){e.printStackTrace ();} P{(m:`N
} a&#Z=WK4
@MtF^y
g]$>G0E`oD
//读取保存的下载信息（文件指针位置） aC]~
private void read_nPos() IL3,dad'^
{ (S5'iksx
try{ mt fDl;/D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O~{Zs\u9
int nCount = input.readInt(); jA=uK6m
nStartPos = new long[nCount]; 7*'_&0
nEndPos = new long[nCount]; >+u5%5-wr
for(int i=0;i<nStartPos.length;i++) dAEz hR[=
{ 5PKv@Mk
nStartPos = input.readLong(); KPW: r#d
nEndPos = input.readLong(); t@}<&{zk
} lxbbyy25
input.close(); 'AeU
} cJ!wZT`
catch(IOException e){e.printStackTrace ();} DbPw)aCj
catch(Exception e){e.printStackTrace ();} 8k_,Hni
} 8C,?Ai<ro
xhUQ.(S`r6
@#VxjXW^
private void processErrorCode(int nErrorCode) 4$IPz7
{ e{=7,DRH<
System.err.println("Error Code : " + nErrorCode); )KXLL;]
} ^Xa-)Pu
8"oS1W
r+m8#uR
//停止文件下载 w/YKWv{_S
public void siteStop() `Yoafa
{ qf)]!wU9
bStop = true; YLPiK
for(int i=0;i<nStartPos.length;i++) WpTC,~-
fileSplitterFetch.splitterStop(); T]CvfvO5
gP/]05$e
1O(fI|gcO
} E_ mgYW*5
} Qx.E+n\
//负责部分文件的抓取 lJ7k4ua\
**FileSplitterFetch.java ? ~_%I
*/ K\?vTgc(
package NetFox; z W+wtYV4
O "{o (
(B$2)yZY
import java.io.*; [c>X Q
import java.net.*; L x9`y t6
QZh8l-!#5
:&_@U$
public class FileSplitterFetch extends Thread { x!I7vs~~zW
<&H.pN1_
{tWfLfzU
String sURL; //File URL A\4Gq
long nStartPos; //File Snippet Start Position F+hsIsQ
long nEndPos; //File Snippet End Position 7RdL/21K
int nThreadID; //Thread's ID _^SNI~
boolean bDownOver = false; //Downing is over VJ;'$SYx
boolean bStop = false; //Stop identical W9eR3q
FileAccessI fileAccessI = null; //File Access interface zaoZCyJT%
]&}?J:+?0E
P_b00",S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )Xg#x:
{ (q +Q.Q
this.sURL = sURL; -O(.J'=8
this.nStartPos = nStart; Q@d X2
this.nEndPos = nEnd; Zqx5I~
nThreadID = id; t$Qav>D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q%t8cJL
} "h:xdaIE/p
[dt1%DD`M
8(g:i#~
public void run() ->93.sge
{ > ]6Eb`v
while(nStartPos < nEndPos && !bStop) bZtjg
{ gVZ~OcB!W
Y9PG
%PkJ7-/b|^
try{ 2Db[dk( ]
URL url = new URL(sURL); -.z~u/uL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4|Z3;;%+
httpConnection.setRequestProperty("User-Agent","NetFox"); kyY tL_SD
String sProperty = "bytes="+nStartPos+"-"; N2~DxVJ5cT
httpConnection.setRequestProperty("RANGE",sProperty); ri\r%x
Utility.log(sProperty); a&y%|Gs^f
ql8CgL
L0uN|?}
InputStream input = httpConnection.getInputStream(); >TtkG|/U-T
//logResponseHead(httpConnection); le8n!Dk(
meIY00
5ue{&z @T
byte[] b = new byte[1024]; t@!oc"z}@
int nRead; d3Y#_!)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ux-Fvwoh
{ .;$/nz6vk
nStartPos += fileAccessI.write(b,0,nRead); .Olq_wuH
//if(nThreadID == 1) 3YRhqp"E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \mv7"TM
} G]5'U"cj3
,gRsbC
w3yI;P
Utility.log("Thread " + nThreadID + " is over!"); 5$zC,g*#
bDownOver = true; [nflQW6
//nPos = fileAccessI.write (b,0,nRead); r$.ek\D5
} zXMIDrq
catch(Exception e){e.printStackTrace ();} >Wy@J]Y#
} ^WM)UZEBC
} [n66ZY#U]
]M= 3Sn8}
,hX03P-X
//打印回应的头信息 H\)on"
public void logResponseHead(HttpURLConnection con) J^1w& 40
{ ,=z8aiUu
for(int i=1;;i++) ^V>sNR
{ [h,T.zpa
String header=con.getHeaderFieldKey(i); [l'~>
if(header!=null) #nn2odR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J}<k`af
Utility.log(header+" : "+con.getHeaderField(header)); O7q-MeMM
else aA0aW=R
break; rXfQ_
} hv7!x=?8
} ks'25tv}F
:9K5zD
iVnrv`k,
public void splitterStop() 3Jk;+<
{ 8[}MXMRdb
bStop = true; .$S`J2Y
} ^9"|tWf6O
N6yqA)z?;
Fc42TH p
} blxH`O!
H}JH339
&*L:4By)]
/* CWt,cwFW
**FileAccess.java j'CRm5O
*//文件访问(定位，写) o_os;
package NetFox; _Z5l Nu
import java.io.*; _0^<)OSY
sDWX} NV
0B1*N_.L@
public class FileAccessI implements Serializable{ Wu:vO2aw8
r~TiJ?8I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *F~"4g
RandomAccessFile oSavedFile; +<@7x16
long nPos; ?$F:S%eH
Qe]@`Vg
[*8wv^
public FileAccessI() throws IOException QoI@/ jLj
{ 8R8J./i.K
this("",0); R7Hn8;..
} %=\h=\wt
T"8>6a@}E
4$d|}ajH
public FileAccessI(String sName,long nPos) throws IOException $U"/.Mh\
{ az0( 54M
oSavedFile = new RandomAccessFile(sName,"rw"); KdYT5VUM/
this.nPos = nPos; fy9{W@E3p
oSavedFile.seek(nPos); /]<0`nI.
} eJ$?T7aUf
duV|'ntr
9?bfZF4A=
public synchronized int write(byte[] b,int nStart,int nLen) `=b*g24z[N
{ :#c?`>uV
int n = -1; m'oVqA&
try{ W[j =!o
oSavedFile.write(b,nStart,nLen); {Kd9}CDAZ
n = nLen; FhAuTZk
} / D#vs9S
catch(IOException e) |PDuvv!.f
{ M+)%gnq`u
e.printStackTrace (); G-bG}9vc]
} 9%kY8#%SV
:14O=C
aSXoYG0\
return n; (fm\kV
} >sPu*8D40a
"p2 $R*ie
/Eh\07p
} RZm5[n
.Eh~$wm
'rp(k\pY
/* &FkKnz4IZ
**SiteInfoBean.java |C7GI[P
*/ yTkYPx
package NetFox; 5j{o0&=_$
'1=/G7g
)'DFDrY
public class SiteInfoBean { jr"yIC_
.eK1xwhJ
`k^ i#Nc>
private String sSiteURL; //Site's URL ;wJLH\/
private String sFilePath; //Saved File's Path REQ2pfk0
private String sFileName; //Saved File's Name 5#$E4k:YV
private int nSplitter; //Count of Splited Downloading File :v1'(A1t
1fViW^l_
[M@i,d-;A
public SiteInfoBean() iDp]lu
{//nSplitter的缺省值为5 *z` {$hc
//default value of nSplitter is 5 {nm#aA%,
this("","","",5); =qCVy:RL4
} '[`.&-;
mrE^D|
SO]x^+[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s-k~_C>Fw
{ +g7Iu! cA
sSiteURL= sURL; `^wF]R
sFilePath = sPath; ;# {XNq<1
sFileName = sName; ]$y"|xqR
this.nSplitter = nSpiltter; Rk2ZdNc\
*~prI1e(
:==kC672
} r_FW)Fu^
I;uZ/cZ|/
8kH'ai
public String getSSiteURL() 84e)huAs
{ qI:}3b;T
return sSiteURL; xqmJPbA
} x%vt$dy*8
^^3 >R`
nU[ROy5
public void setSSiteURL(String value) s-*8=
{ wV W+~DJ
sSiteURL = value; ) ;-AT^
} PX\}lTJ
csH1X/3ha\
,yAvLY5P
public String getSFilePath() `r+e!o
{ lv&<kYWY
return sFilePath; Ij@YOt
} N%_-5Q)so
dH&N<
76zi)f1f
public void setSFilePath(String value) Lo7R^>
{ Z&JW}''n|F
sFilePath = value; :*A6Ba
} A}H)ojG'v
3::DURkjf
8'Z9Z*^h#x
public String getSFileName() xJ^Gtq Um
{ <y-KWWE
return sFileName; Eq~&d.j
} 'u_'y
M!!W>A@T[g
S[X bb=n
public void setSFileName(String value) D-E30b]e
{ s-o0N{b?#'
sFileName = value; jP@H$$-=wH
} (`!?p ^>A
@e$zEj5
Y;xVB" (
public int getNSplitter() 4SY]Q[
{ .QRQvtd.
return nSplitter; H5^'J`0\
} ]*ZL>fuD|
42ttmN1F
9_5Fl,u z
public void setNSplitter(int nCount) 0K@s_C=n#
{ o-GlBXI;
nSplitter = nCount; x_2 [+Ol
} yZUB8erb.
} 8iqx*8}
6$9n_AS
`fY~Lv{4d_
/* "Z&{
**Utility.java 9~ K1+%!
*/ 7W5FHZd'
package NetFox; M-T&K%/lW
.!l#z|/x
wu/]M~XwI
public class Utility { Z+(V'e;
jiC;*]n
b H?dyS6Bx
public Utility() 'fy1'^VPAV
{ [-{L@
|Y0BnyGK
0p*(<8D}
} A_CEpG]
Ac^}wXp
//线程睡眠 )l\BZndf
public static void sleep(int nSecond) x\*`i)su
{ `.#e4 FBW
try{ 0 #VH=pga
Thread.sleep(nSecond); N6Vn/7I5%
} Uj(,6K8W
catch(Exception e) iVFHr<zk
{ IgG@v9'
e.printStackTrace (); zX{[Z
} w`CGDF\Oo
} t(\d;ybyx
K0g<11}(Yg
//日志 I}kx;!*b
public static void log(String sMsg) ,fT5I6l
{ X%h1r`h&
System.err.println(sMsg); T,TKt%
} &g\D-At
kbI:}b7H
<q~&g &&+
public static void log(int sMsg) |F iL1_
{ q\x*@KQgM
System.err.println(sMsg); _`+ !,kG[
} ;v[F@O~*)
} Fm#4;'x5E
wbUpD(
cW/RH.N
/* DCACj-f
**TestMethod.java (=j]fnH?
*/ w5bD
package NetFox; Vv B%,_\
^;Nu\c
B;SYO>.W
public class TestMethod { >Yl?i&3n
IMmoq={(z
I%h9V([
public TestMethod() %t([
{ ///xx/weblogic60b2_win.exe </5uB' B ^
try{ :5L9tNr{_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PB.@G,)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4l@*x^F
SiteFileFetch fileFetch = new SiteFileFetch(bean); xx)egy_
fileFetch.start(); aW$sd)
} pUZbZ U
catch(Exception e){e.printStackTrace ();} V44IA[
&y[Od{=
S#/[>Cb
} z:ue]7(.
5%mc|
/[#<@o
public static void main(String[] args) X|{TwmHd
{ @SF*Kvb&
new TestMethod(); 2ro4{^(_
} f]tc$`vb
} u7=`u/
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