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)); `+t.!tv!
} l~D N1z6`
for(int i=0;i<nEndPos.length-1;i++) >6oOZbUY0
{ it>r+%
nEndPos = nStartPos[i+1]; I+ es8
} nuoPg3Nl
nEndPos[nEndPos.length-1] = nFileLength; TRZRYm"
} JT9N!CGZ
} $!5\E>y#
bWZbG{Y.
VyRsPg[(
//启动子线程 v4RlLgdS%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i/b'4o=8
for(int i=0;i<nStartPos.length;i++) XX1Il;1G#
{ l<Q>N|1#k%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |oub!fG4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d*oUfiW
nStartPos,nEndPos,i); DI`%zLDcY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,-+"^>
fileSplitterFetch.start(); j F-v%?
} tTN?r8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dfd-^N!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k'$!(*]\b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k8,?hX:
nEndPos = " + nFileLength); s/:Fwr4q#a
// fileSplitterFetch[nPos.length-1].start(); p'sc0@}_O
84i_k
3+J0!FVla
//等待子线程结束 v|ox!0:#
//int count = 0; w'X]M#Q><
//是否结束while循环 oo=#XZkk
boolean breakWhile = false; *_ +7ni
'xv8Gwf"
=&!HwOnp
while(!bStop) tA$)cg+.
{ <`!PCuR
write_nPos(); Qm8)4?FZ
Utility.sleep(500); `VQb-V
breakWhile = true; |0{u->+ )
O)kgBrB
!;6Jng%
for(int i=0;i<nStartPos.length;i++) \@}#Gez
{ ri1C-TJM)
if(!fileSplitterFetch.bDownOver) q8:{Nk
{ E42eOGp9i
breakWhile = false; @<M*qK1h
break; B/Gd(S`@q
} -[OXSaf6
} Omi^>c4G
if(breakWhile) $|$e%
break; |wox1Wt|E
;WT{|z
m,')&{Rd
//count++; 24Z]%+b*E
//if(count>4) Y${l!+q
// siteStop(); O[9-:,B{w
} }j1!j&&
5]1leT
?3Ij*}_O2
System.err.println("文件下载结束！"); #Fu>|2F|
} .+y>8h3{
catch(Exception e){e.printStackTrace ();} ;nmM7TZ;
} l{ex?
M}0eu(_|
3`HnLD/
//获得文件长度 w(1Gi$Z(Q)
public long getFileSize() VGw(6`|!
{ :)jJge&^p
int nFileLength = -1; ;Qi }{;+
try{ .bf<<+'o
URL url = new URL(siteInfoBean.getSSiteURL()); 9kKnAf4Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D\^WXY5e%y
httpConnection.setRequestProperty("User-Agent","NetFox"); xjdw'v+qZo
2JmZ{
JNWg|Qt
int responseCode=httpConnection.getResponseCode(); A>NsKWf{
if(responseCode>=400) yBLUNIr
{ }<MR`h1
processErrorCode(responseCode); +:6Ii9GN
return -2; //-2 represent access is error &X`u9 V
} 5j"1z1_&
6@tvRDeaDW
Ni*Wz*o
String sHeader; .BO<
4c~>ci,N?(
Bn]K+h\E
for(int i=1;;i++) 5/m$)wE
{ <-UOISyf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J NC
//Utility.log(in.readLine()); ^TXfsQs
sHeader=httpConnection.getHeaderFieldKey(i); Swtbl`,
if(sHeader!=null) :9l51oE7
{ 1u]P4Gf=
if(sHeader.equals("Content-Length")) p4VqV6LwD
{ }8'&r(cN4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |0bc$ZY:
break; <Wl(9$
} ,/&Zw01dGN
} }tST)=M`
else %up}p/?
break; ;52'}%5
} V'Qn sI
} km:nE: |
catch(IOException e){e.printStackTrace ();} %@ mGK8
catch(Exception e){e.printStackTrace ();} i(2y:U3[@
Z\>, ),O
{bF1\S]2
Utility.log(nFileLength); 0)uYizJce
Y9r3XhVI
}bB`(B,m
return nFileLength; h3u1K>R)
} =Pe><k
ED![^=
NWmtwS+@
//保存下载信息（文件指针位置） 7z~Ghz
private void write_nPos() 9x~-*8aw
{ OIaYHA
try{ <o:@dS
output = new DataOutputStream(new FileOutputStream(tmpFile)); [JTto!Ih$
output.writeInt(nStartPos.length); U;xF#e
for(int i=0;i<nStartPos.length;i++) 0vs0*;F;
{ (7$$;
// output.writeLong(nPos); O>DNC-m)i{
output.writeLong(fileSplitterFetch.nStartPos); =~FG&rk^
output.writeLong(fileSplitterFetch.nEndPos); (N~$x
} ){Mu~P
output.close(); SKXBrD=-
} _JGs}aQ
catch(IOException e){e.printStackTrace ();} j kn^Z":
catch(Exception e){e.printStackTrace ();} ~krS#\
} ?~ULIO'
cep$_Ja
~waNPjPRG
//读取保存的下载信息（文件指针位置） M<8ML!N0;t
private void read_nPos() O ++/ry%k
{ N=,j}FY
try{ eE:&qy^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LhJa)jFQ
int nCount = input.readInt(); 1]4^V7y
nStartPos = new long[nCount]; u@ N~1@RT|
nEndPos = new long[nCount]; k1N$+h ;\
for(int i=0;i<nStartPos.length;i++) B0mLI%B
{ gb-{2p>}
nStartPos = input.readLong(); Yx?aC!5M
nEndPos = input.readLong(); -rY 7)=
} Ya4?{2h@+
input.close(); M^SuV
} mv Ov<x;l
catch(IOException e){e.printStackTrace ();} ~I_owCVZ
catch(Exception e){e.printStackTrace ();} EZr6oO@Nc
} 9q4_j
zjM/M
XQ;I,\m
private void processErrorCode(int nErrorCode) ['Z{@9
{ <O857j
System.err.println("Error Code : " + nErrorCode); `6w#8}
} (6xDu.u?A
iQ`]ms+
DvT+`X?R
//停止文件下载 Y_H/3?b%
public void siteStop() Ky9W/dCR
{ -Wjh**
bStop = true; K}x/ BhE+
for(int i=0;i<nStartPos.length;i++) yqcM(,0]
fileSplitterFetch.splitterStop(); tEhr
lH1g[ ))
()|3
} Enj_tJs
} .|]IwyD &
//负责部分文件的抓取 !*a[jhx
**FileSplitterFetch.java [e4![G&y`
*/ 6$e]i|e
package NetFox; G%hO\EO
wly>H]i'
Q-('5a19J
import java.io.*; :1<~}*B@{
import java.net.*; 3IyZunFT
Pz~q%J
pC^[[5A
public class FileSplitterFetch extends Thread { M<oA<#IW
xdF guV8
,{<Fz%
String sURL; //File URL O~'FR[J
long nStartPos; //File Snippet Start Position {\We72!
long nEndPos; //File Snippet End Position !t-K<'
int nThreadID; //Thread's ID yq*JdTF
boolean bDownOver = false; //Downing is over fi=?n{e'
boolean bStop = false; //Stop identical H-&3}
FileAccessI fileAccessI = null; //File Access interface <aVfJd/fT
k=uZ=tUft*
sv=^k(d3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B_~jA%0m'
{ P4%>k6X
this.sURL = sURL; nPf'ee
this.nStartPos = nStart; euZ(}+N&
this.nEndPos = nEnd; ?`. XK}
nThreadID = id; M_&4]\PkCy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T|+$@o
} |\{Nfm=:%
OOLe[P3J3
pG28M]\
public void run() >UN vkQ:
{ hWxT!
while(nStartPos < nEndPos && !bStop) iwo$\
{ ~07RFR
8A/>JD3^
;Q90Y&{L=$
try{ TcZN%
URL url = new URL(sURL); H-a^BZ&iU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -A;w$j6*
httpConnection.setRequestProperty("User-Agent","NetFox"); "^"'uO$
String sProperty = "bytes="+nStartPos+"-"; @XBH.A^7r
httpConnection.setRequestProperty("RANGE",sProperty); q)oN2-
Utility.log(sProperty); E\!n49
>Z"9rF2SW
+S0u=u65
InputStream input = httpConnection.getInputStream(); ,>w}xWSYpG
//logResponseHead(httpConnection); 6+ANAk
{Q<0\`A
%BICt @E
byte[] b = new byte[1024]; Q?]w{f(
int nRead; 4?]ZV_BD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1PIzV:L\
{ >)sqh ~P
nStartPos += fileAccessI.write(b,0,nRead); |8'B/ p=
//if(nThreadID == 1) u_Zm1*'?B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 85C#ja1&
} 5G oK"F0i
f!!P
NDW8~lkL
Utility.log("Thread " + nThreadID + " is over!"); Lupy:4AD
bDownOver = true; Xq%*#)M;
//nPos = fileAccessI.write (b,0,nRead); O\JD,w
} jJ-d/"(
catch(Exception e){e.printStackTrace ();} V0T<eH<
} oT!/J
} 9<Ag1l
z5ZKks
]umZJZ#Y
//打印回应的头信息 *o2#eI
public void logResponseHead(HttpURLConnection con) -fQX4'3R
{ *I/A,#4r
for(int i=1;;i++) gPp(e j7
{ /.)2d8,
String header=con.getHeaderFieldKey(i); )-)pYRlO
if(header!=null) u#!GMZJN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H9:%6sds
Utility.log(header+" : "+con.getHeaderField(header)); 8>dq=0:
else qxSs ~Qc
break; ##2`5i-x
} "B?R| Xg
} D{W SKn
S|) J{~QH
@Q3, bj
public void splitterStop() %xpd(&)n
{ sSy$(%
bStop = true; \Nyr=<c
} AtT"RG-6
9nO(xJ"e4
7y>(H<^>
} pMDH
{70Ou}*
G V=OKf#
/* Md?acWE*L
**FileAccess.java c+wuC,
*//文件访问(定位，写) WN1Jm:5YV
package NetFox; ]'6'<S
import java.io.*; K7S754m
O&52o]k5l
_ flgQ
public class FileAccessI implements Serializable{ i<Q& D\Pv
OMi02tSm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p&QmIX]BZ
RandomAccessFile oSavedFile; W0U`Kt&~a
long nPos; /t$*W\PL@
niQ+EAD
hi0XVC95
public FileAccessI() throws IOException B#Qpd7E+*
{ r:.6"VQu}
this("",0); |;~nI'0O])
} p!QR3k.9s
I}rGx
h&q=I.3O|?
public FileAccessI(String sName,long nPos) throws IOException 7^&lbzVbm(
{ wFp~
oSavedFile = new RandomAccessFile(sName,"rw"); ` %l&zwj>
this.nPos = nPos; 7x%S](m%
oSavedFile.seek(nPos); ['?^>jfr
} 48:liR
\+G.]|"Y
K_Z+]]$#
public synchronized int write(byte[] b,int nStart,int nLen) 8V,"Id][
{ p8$\uo9YQ
int n = -1; :|zp8|
try{ ~K_]N/ >
oSavedFile.write(b,nStart,nLen); ,RR;VKj
n = nLen; [6G=yp
} :&qC<UD
catch(IOException e) Kq8(d`g}
{ sC!1B6:
e.printStackTrace (); FoQ?U=er
} 4v0dd p
KUlB2Fqi
"OVi /:*B
return n; 0 -!?W
} `S5>0r5[
g%+ql[(4
GA(OK-WUd
} 4P`PmQ=GQh
8I<_w4fC
>).@Nb;e
/* sE^ns\&QP=
**SiteInfoBean.java =.VepX|?D
*/ Th.3j's
package NetFox; yB 1I53E
B,r5kQI4
V[4(~,9
public class SiteInfoBean { KSF5)CZ5
G% o7BX
H]Y#pLu|
private String sSiteURL; //Site's URL i<'{Y
private String sFilePath; //Saved File's Path ~K4k'
private String sFileName; //Saved File's Name |GJBwrL^0
private int nSplitter; //Count of Splited Downloading File 7zOhyl?
h_AJI\{"
#8S [z5 `
public SiteInfoBean() A1mYkG)l
{//nSplitter的缺省值为5 7qW.h>%WE
//default value of nSplitter is 5 u![4=w
this("","","",5); FP.(E9
} <GSQ2bX[
H<v c\r
|*lH9lWJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A$%@fO.b
{ ],!\IqO
sSiteURL= sURL; JJ^iy*v
sFilePath = sPath; A"Tc^Ij
sFileName = sName; (r.$%[,.<
this.nSplitter = nSpiltter; V#p G; ,
9"m,p
qJ#L)
} |3s.;wK
*K]>}
eUX@9eML
public String getSSiteURL() C}x4#bNK
{ Kh>?!`lL
return sSiteURL; 0*37D5jH
} 3FGbQ_
#k"1wSx16
}".\ 4B$n
public void setSSiteURL(String value) tpN]evp|
{ B)(p9]q
sSiteURL = value; nwZ[Ygl|
} d,Hf-zJ%~
j4.Qvj >:4
$I?=.:<+
public String getSFilePath() Bq~AU#
{ \W3+VG2cA
return sFilePath; s#'|{
} 43UJ#rF
bx+(.F
NTXws4'D
public void setSFilePath(String value) {Bav$kw;?e
{ m~Lf^gbG?
sFilePath = value; J`U$b+q6
} =g{_^^n
4v rm&k
#R~">g:w
public String getSFileName() g_3rEvf"4
{ O JZ!|J8?
return sFileName; pkrl@jv >
} f]@[4<Ny
!Ei Ze.K
AlPL;^Y_l
public void setSFileName(String value) O^QR;<t'
{ P^'>dOI0w
sFileName = value; \#h})`
} `D&#U'wB
Bbn832iMUY
#o(?g-3
public int getNSplitter() *!-}lc^4
{ h$#4ebp
return nSplitter; (.jO:#eE%
} ?^e*UJNM
e B9m4
;j[q?^ b
public void setNSplitter(int nCount) 7)ES!C
{ &F@tmM~
nSplitter = nCount; ;/6:lL
} {,nd_3"Vq
} |THkS@Br
%8bFQNd
~FK+bF?%
/* rRF+\cP?.
**Utility.java $g}/T_26
*/ Mt7X<?GZm
package NetFox; #R"9)vHp
]5qjK~,4b
brpN>\
public class Utility { [A.eVuV;+
Rx_,J%0Fq
rm7*l<v6
public Utility() 'tq\<y
{ M8^ziZY
S[\cT:{OE
ThT.iD[
} m%BMd
jS5t?0
//线程睡眠 #=)?s 8T
public static void sleep(int nSecond) UC?2mdLt^
{ @n~ND).
try{ RN cI]oJ
Thread.sleep(nSecond); N@%xLJF=N>
} o$qFa9|Ec?
catch(Exception e) Yp?a=R
{ qqO10~Xc
e.printStackTrace (); 8&`T<ECq>
} v]d?6g
} A7I8Z6&
7@e[:>e
//日志 U3VsMV*Y
public static void log(String sMsg) j3V"d3)
{ R[ +]d|L
System.err.println(sMsg); MOH,'@&6^
} do:RPZ!
[8om9 Z3
BhhK|U/
public static void log(int sMsg) ;r2b@x:<_
{ CM@"lV_
System.err.println(sMsg); 6P/9Vh j'
} k^vmRe<lk
} OM.(g%2
,rvZW}=
SquqaX+<
/* Z)Xq!]~/g
**TestMethod.java pqNoL* H
*/ Di5Op(S((
package NetFox; B=nx8s
/fcwz5~
#!F8n`C-
public class TestMethod { s3fGX|;
@%5F^Vbd
M#22Zfxq
public TestMethod() %Tm'aY"
{ ///xx/weblogic60b2_win.exe X~/9Vd g
try{ YRT}fd>R&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sjVl/t`l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 07HX5 Hd
SiteFileFetch fileFetch = new SiteFileFetch(bean); =,}!Ns{k
fileFetch.start(); 2[bR6 T89
} hF{mm(qyv
catch(Exception e){e.printStackTrace ();} k+>p!1
U]R|ej
>=RHE@
} ~A{[=v
K`AW?p^$Y
^,\se9=(
public static void main(String[] args) H"Em|LX^
{ :fMM-?s]
new TestMethod(); I?xhak1)lu
} ^LAS9K1.
} &opH\wa
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