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)); 4"d,=P.{
} 7=G2sOC
for(int i=0;i<nEndPos.length-1;i++) S$6|KY u
{ ewZ?+G+m
nEndPos = nStartPos[i+1]; 2w?q7N%
} 44]s`QyG
nEndPos[nEndPos.length-1] = nFileLength; o<`vh*U@,4
} C"hN2Z!CD|
} @KN+)qP
#lYyL`B+~
P*|N)S)X%
//启动子线程 q!Du J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A~zn;
for(int i=0;i<nStartPos.length;i++) cG|fau<G
{ U( YAI%O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +&GV-z~o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #NS|9jW
nStartPos,nEndPos,i); 6x+ujUBkK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i_Kwxn$
fileSplitterFetch.start(); i2F7O"f.
} Ss3p6%V/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^QK`z@B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); twT/uBQ4a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -'rdN i
nEndPos = " + nFileLength); X+hHEkJ
// fileSplitterFetch[nPos.length-1].start(); Z%t_1t
6FUW^dt
YEL0h0gn
//等待子线程结束 })g<I+]Hf9
//int count = 0; ]33!obM
//是否结束while循环 TOwd+]B
boolean breakWhile = false; &?<uR)tl
X Xque-
dkQ4D2W*\
while(!bStop) TCr4-"`r-{
{ ^Hd[+vAvR
write_nPos(); ]a $6QS
Utility.sleep(500); j\2Qe%d
breakWhile = true; SSK}'LQ
?=u?u k<-
)M0YX?5AR
for(int i=0;i<nStartPos.length;i++) r`H}f#.KR
{ #M,&g{
if(!fileSplitterFetch.bDownOver) inh0p^
{ p{f R$-d
breakWhile = false; HJL! ;i
break; ,OE&e*1
} Hon2;-:]{]
} |'^s3i&w
if(breakWhile) %iyc1]w{
break; 1\}vU
FO!Td
A*JOp8\)
//count++; /{T&l*'
//if(count>4) iaGA9l<b
// siteStop(); j=WxtMS
} coP->&(@U#
+m=b "g
qeZG/\,
System.err.println("文件下载结束！"); l:HQ@FX
} .OPknC
catch(Exception e){e.printStackTrace ();} ,Qj G|P
} 727#7Bo
S%SYvA
*x36;6~W;
//获得文件长度 Llfl I
public long getFileSize() \)PB p
{ E`HoJhB
int nFileLength = -1; -hd
try{ L.n@;*
URL url = new URL(siteInfoBean.getSSiteURL()); ]'.qRTz'\t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \CB^9-V3
httpConnection.setRequestProperty("User-Agent","NetFox"); !np_B0`
|t,sK aL
,=/9Ld2w9
int responseCode=httpConnection.getResponseCode(); ,Py\Cp=Dw
if(responseCode>=400) Sd+5Uf`
{ qv!(In>u
processErrorCode(responseCode); K#3^GB3P
return -2; //-2 represent access is error :1'
} L+t / E`
26V6Y2X
T(!1\TB
String sHeader; *zrT;jG
m&)/>'W
$LP(\T([
for(int i=1;;i++) /[R=-s ;
{ * #yF`_p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K\xz|Gq
//Utility.log(in.readLine()); V@'Xj .ze
sHeader=httpConnection.getHeaderFieldKey(i); `M@ESA(e
if(sHeader!=null) p=+Y7NE)
{ xP8/1wd.
if(sHeader.equals("Content-Length")) 0h-NT\m
{ &;Ncc,jb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O,$*`RZpx
break; z#{Y>.b
} FZ*"^=)`G
} I4Do$&9<D
else CD1Ma8I8
break; R|?n
} Np\NStx2
} snbXAx1L
catch(IOException e){e.printStackTrace ();} #}A"yo
catch(Exception e){e.printStackTrace ();} ={g"cx
Et6j6gmif
q<}IO
Utility.log(nFileLength); h#1:ypA6l
[^"}jbn/
)nd^@G^
return nFileLength; vJE=H9E
} *|&Y ,H?
g *5_m(H
g[cnaS|?
//保存下载信息（文件指针位置） u#6s^ )W
private void write_nPos() {i>AQ+z61f
{ !@C-|=9G
try{ MN: {,#d0
output = new DataOutputStream(new FileOutputStream(tmpFile)); #}Qe{4L
output.writeInt(nStartPos.length); /_{-~0Z=@B
for(int i=0;i<nStartPos.length;i++) Df"PNUwA"
{ w1Bkz\95
// output.writeLong(nPos); rCJ$Pl9R
output.writeLong(fileSplitterFetch.nStartPos); .ATpwFal
output.writeLong(fileSplitterFetch.nEndPos); 3.movkj
} ]&D dy&V
output.close(); ,[n9DPZ
} }B%9cc
catch(IOException e){e.printStackTrace ();} *r.%/^@
catch(Exception e){e.printStackTrace ();} >s<Bu'r
} +2[0q% i
9KK^1<46c
/&6{}n
//读取保存的下载信息（文件指针位置） [3dGHf;miw
private void read_nPos() ,Uh^e]pC
{ +9/K|SB{$
try{ "8Dm7)nB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lz^Vi!|p
int nCount = input.readInt(); m%9Yo%l~
nStartPos = new long[nCount]; _DR@P(0>_
nEndPos = new long[nCount]; 7[e-3
for(int i=0;i<nStartPos.length;i++) NSVE3
{ rBJ`=oz
nStartPos = input.readLong(); Xl=RaV^X"
nEndPos = input.readLong(); $YJ 1P
} @5d^ C
input.close(); 6{I7=.V
} F`KXG$
catch(IOException e){e.printStackTrace ();} KKwM\
catch(Exception e){e.printStackTrace ();} VjM/'V5
} @@ j\OR
\p:)Cdn
2K4Xu9-i:b
private void processErrorCode(int nErrorCode) <v1H1'gv
{ Boj R"
System.err.println("Error Code : " + nErrorCode); &n*ga$Q
} "Lvk?k )hx
(~Z&U
[l=@b4Og
//停止文件下载 E"}%$=yK
public void siteStop() \LUW?@gLa
{ }a OBQsnO
bStop = true; (o{Y;E@/y
for(int i=0;i<nStartPos.length;i++) A":=-$)
fileSplitterFetch.splitterStop(); ^aqQw u
YM#'+wl}`
"s@Hg1
} 1PVZGZxAgv
} 'qVlq5.
//负责部分文件的抓取 ts=D
**FileSplitterFetch.java }:?*n:g5
*/ IlF_g`
package NetFox; X$<pt,}%
U_jW5mgsG
PU%Zay
import java.io.*; R(t%/Hvs$
import java.net.*; *vQ 6LF;y
e"1mdw"
.joCZKO
public class FileSplitterFetch extends Thread { iK2f]h
#@nPB.
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String sURL; //File URL H/t0#
long nStartPos; //File Snippet Start Position #0)TS
long nEndPos; //File Snippet End Position 6l,6k~Z9
int nThreadID; //Thread's ID O0y0'P-rJq
boolean bDownOver = false; //Downing is over I!b"Rv=Nf-
boolean bStop = false; //Stop identical ju:}%'
FileAccessI fileAccessI = null; //File Access interface kM-8%a2i
vEjf|-Mb9
R;,5LS&*a
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException shGUG;
{ _I)TO_L;
this.sURL = sURL; uv5NqL&
this.nStartPos = nStart; q'fOlq
this.nEndPos = nEnd; ^G qO>1U
nThreadID = id; xqdkc^b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 krGIE}5
} g3s5ra[
?i_2ueVR
Vuy%7H
public void run() ((?"2 }1r
{ TlO=dLR7d
while(nStartPos < nEndPos && !bStop) Obu 6k[BE.
{ =2*2$
_e8Gt6>
P:J|![
try{ }A6z%|d
URL url = new URL(sURL); G;u 6p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3]iw3M
httpConnection.setRequestProperty("User-Agent","NetFox"); f7zB_hVDmE
String sProperty = "bytes="+nStartPos+"-"; o^5UHFxTCB
httpConnection.setRequestProperty("RANGE",sProperty); g[y&GCKY!=
Utility.log(sProperty); lhQMR(w^
r:rPzq1
5~>j98K
InputStream input = httpConnection.getInputStream(); ~Y0K Wx4
//logResponseHead(httpConnection); TN Z-0
-~sW@u)O
f*V^HfiQb
byte[] b = new byte[1024]; p Dg!Cs
int nRead; io"NqR#"v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XiV*d06{
{ J*ofa>
nStartPos += fileAccessI.write(b,0,nRead); Za,o
//if(nThreadID == 1) 0(C[][a*u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (gdzgLHy
} 3p-SpUvp
.: wg@Z
RYl{89
Utility.log("Thread " + nThreadID + " is over!"); cEXd#TlY~X
bDownOver = true; ui"`c%2n
//nPos = fileAccessI.write (b,0,nRead); 1C=42ZZ&2
} gjiS+N[
catch(Exception e){e.printStackTrace ();} EGRIhnED#
} @<OsTF L
} P;7[5HFF
od@!WjcM[8
* W"Pv,:
//打印回应的头信息 aA%x9\Y
public void logResponseHead(HttpURLConnection con) ?y%Mm09
{ 8u*Q^-fpo0
for(int i=1;;i++) xt@v"P2Ok
{ (RUc>Qi
String header=con.getHeaderFieldKey(i); )-6>!6hZ
if(header!=null) SXXO#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \HMuVg'Q
Utility.log(header+" : "+con.getHeaderField(header)); pcd?6jh8
else ?!tO'}?
break; lh\`9F:
} uI)z4Z
} +CQIm!Sp
g5nL7;`N
/w5c:BH
public void splitterStop() %}
{ yp hd'Pu"
bStop = true; @Rd`/S@
} E)'T;%
uw>y*OLU+
mmC MsBfL
} _0&U'/cs
#pD=TMefC
uYE"OUNWL
/* IQ JFL +f
**FileAccess.java R{B5{~m>W@
*//文件访问(定位，写) qP/McH?
package NetFox; Kk% IN9
import java.io.*; 25vq#sS]
)Zvn{
rv~OfL
public class FileAccessI implements Serializable{ I'J-)D`
JFRbWQ0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U d+6=Us{
RandomAccessFile oSavedFile; U,<?]h
long nPos; q)"yP\
M VE:JNm
#E/|WT
public FileAccessI() throws IOException +D h?MQt?
{ =4/K#cQ
this("",0); %u?A>$Jn
} (>\4%(pnD
;MO,HdP;
=EHKu|rX~
public FileAccessI(String sName,long nPos) throws IOException P!R`b9_U
{ ?R@u'4yK
oSavedFile = new RandomAccessFile(sName,"rw"); V4*/t#L/
this.nPos = nPos; _k)EqPYu@
oSavedFile.seek(nPos); }o=s"0a
} 3|Y.+W
;%/}(&E2
_:XX+3W7
public synchronized int write(byte[] b,int nStart,int nLen) gp\o|igT
{ %pxHGO=)E
int n = -1; %8KbVjn
try{ cS",Bw\
oSavedFile.write(b,nStart,nLen); 5n=~l[O
n = nLen; wWJM./y
} -+Ox/>k
catch(IOException e) ocj^mxh=O
{ tY`%vI [
e.printStackTrace (); S8e?-rC
} YB9)v5Nz(
K &G
#!jwn^yq
return n; a/~1CrYr
} 2Gc0pBqx
RbEtNwG@c
na|23jz4
} K!tM "`a
5BMrn0
;C5 J^xHI
/* ](k}B*Abh
**SiteInfoBean.java ?[8s`caK.
*/ ?2S<D5MSb
package NetFox; Cyp%E5b7
'Y5l3xQk
%PM8;]
public class SiteInfoBean { WQNFHRfO*n
{%v{iE>
Mgux(5`;
private String sSiteURL; //Site's URL fp$U%uj
private String sFilePath; //Saved File's Path 2()/l9.O'
private String sFileName; //Saved File's Name Y-v6M3$
private int nSplitter; //Count of Splited Downloading File ^B'N\[
$btk48a7
P\2x9T
public SiteInfoBean() N}\3UHtO
{//nSplitter的缺省值为5 !h+VbZ
//default value of nSplitter is 5 -pN'r/$3V
this("","","",5); 5"7lWX
} i)MJP*
`_.(qg
ej]>*n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'Fa~l'G7X
{ cx+%lco!
sSiteURL= sURL; hx!hI1
sFilePath = sPath; aB~=WWLR\
sFileName = sName; P?M WT]fY
this.nSplitter = nSpiltter; Hg+bmwM
7HQ|3rt
10..<v7
} R5rCCp
l7S&s&W @
+{&++^(}a
public String getSSiteURL() I*= =I4qx
{ z?g\w6
return sSiteURL; y.WEO>
} 9y;8JO
6z1>(Za7>
QzD8 jk#
public void setSSiteURL(String value) 'zx1kq1
{ O.'\GM
sSiteURL = value; i/q1>
} 6$\'dkufQ
w*IDL0#
X[$FjKZh=F
public String getSFilePath() L[}Ak1 A
{ 6cTd SE
return sFilePath; Eh.NJI(
} @l@erCw@
hv9k9i7@l
f26hB;n
public void setSFilePath(String value) JrwR:_+|
{ kSU]~x
sFilePath = value; '>dx~v %
} fqD1Ej
JX2@i8[~
u|M_O5^
public String getSFileName() oGqbk x
{ YjwC8#$
return sFileName; (-hGb:
} 5c6?$v/
yxL(mt8
HpR(DG) ?
public void setSFileName(String value) nB#XQ8Nzx^
{ nrRP1`!]T
sFileName = value; ;Km74!.e7
} f]]UNS$AYQ
2sahb#e )
.L))EB
public int getNSplitter() 9\a;75a
{ "tg?V
return nSplitter; pcO0xrI
} vFl06N2
61&A`
(@;=[5+
public void setNSplitter(int nCount) 5YnTGf&
{ Ce!xa\
nSplitter = nCount; '(yjq<
} 05/'qf7P,U
} E@92hB4D"
z3Q#Wmv2
Gq9pJ
/* I?Ct@yxhF'
**Utility.java b=Oec%Adx
*/ }ujl2uhM
package NetFox; >sm<$'vZ/
-)$5[jM]
)~H&YINhn
public class Utility { +:#UU;W
nx'Yevi0$
nypG
public Utility() m}o4Vr;"
{ ;]sbz4?
&u~#bDh
Tt\G y
} (|.rEaTA[1
oS Apa
//线程睡眠 O#B2XoZa+
public static void sleep(int nSecond) OCN@P+L3q
{ wJu,N(U
try{ vC>8:3Zaq
Thread.sleep(nSecond); 8AuOe7D9A
} Q,<V)
catch(Exception e) VVDd39q
{ RGV}c#
e.printStackTrace (); < r7s,][&
} IH$ZPux
} CKr5L
?)?}^
//日志 #Zt(g(T
public static void log(String sMsg) xmBGZ4f%
{ B4 +A
System.err.println(sMsg); U)iq
} s\3OqJo%)
TIYo&?Z)
jltW@co2sV
public static void log(int sMsg) Y;[+^J*a
{ vvmG46IgZ
System.err.println(sMsg); b_rHt s
} v2;'F
} dxK3462
P1IL]
c%vtg.A
/* n,8bQP=&
**TestMethod.java XAw0Nn
*/ xmNs<mz
package NetFox; e]q(fPK
y,cz;2
<%GfF![v
public class TestMethod { 3T84f[CFJ
br4?_,
1XPYI
public TestMethod() }\3jcnn
{ ///xx/weblogic60b2_win.exe \_8.\o"@*#
try{ 9U]j@*QN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W}aCU~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;?.w!|6
SiteFileFetch fileFetch = new SiteFileFetch(bean); 32x[6"T
fileFetch.start(); hG8<@
} lNba[;_
catch(Exception e){e.printStackTrace ();} s5 ($b
$ n"*scyI
wjc&S'[
} w~wg[d
"'v^X!"
!@4 i:,p@
public static void main(String[] args) W|4h;[w
{ 28x:]5=jb
new TestMethod(); + [~)a4#
} fe8}2#<o
} 2pmqP-pKd
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