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)); >lg-j-pV
} O?I~XM'S
for(int i=0;i<nEndPos.length-1;i++) ">V.nao
{ yu>DVD
nEndPos = nStartPos[i+1]; ~ d!F|BH4
} /^F$cQX(
nEndPos[nEndPos.length-1] = nFileLength; ]IZn#gnM
} ',<Bo{
} zLB7'7oP
X\dPQwasM
~c*$w O\
//启动子线程 8ezdU"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G6?+Qzr
for(int i=0;i<nStartPos.length;i++) !gm;g}]szG
{ %1Pn;bUU!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !qjIhZi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M],}.l
nStartPos,nEndPos,i); >,V~-Tp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K4V\Jj1l
fileSplitterFetch.start(); f4Yn=D=_
} Q#} 0pq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1dgy-$H~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wx,yx3c (
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `l0&,]
nEndPos = " + nFileLength); 4Sq[I
// fileSplitterFetch[nPos.length-1].start(); &1:_+
4)i(`/U
:XP/`%:
//等待子线程结束 M-Tjp'=*
//int count = 0; @D3Y}nR:
//是否结束while循环 `- \J/I
boolean breakWhile = false; e{<r<]/j
+v7mw<6s
fA k]]PU
while(!bStop) ^lp#j;Df
{ nhm)P_p
write_nPos(); e[(XR_EY
Utility.sleep(500); mEUdJvSG(
breakWhile = true; rrSsQq
(<"uV%1
*C*'J7
for(int i=0;i<nStartPos.length;i++) jM'kY|<g;
{ c9c_7g'q-
if(!fileSplitterFetch.bDownOver) >)&]Ss5J
{ S-$N!G~!
breakWhile = false; :E>"z6H
break; \:To>A32
} v9<'nU WVR
} 0E5"}8
if(breakWhile) 2;z~xR
break; E W{vF|
zP8a=Iv
nSM8o<)H
//count++; M!9gOAQP
//if(count>4) U>,E]'
// siteStop(); /g_cz&luR
} M'n2j
p:GB"e9>H
b3Uw"{p
System.err.println("文件下载结束！"); fXV+aZ
} xxsax/h
catch(Exception e){e.printStackTrace ();} 7l%]/`Y-
} S{qc1qj
>+P5Zm(_
QQnpy.`:/
//获得文件长度 ^Pq4 n%x
public long getFileSize() o<Esh;;*nm
{ -Dx_:k|k
int nFileLength = -1; %l#i9$s
try{ T;f`ND2fY
URL url = new URL(siteInfoBean.getSSiteURL()); 94>EA/+Ek
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DaN=NURDV
httpConnection.setRequestProperty("User-Agent","NetFox"); 4DYa~ =w
KXQ &u{[<
)H'SU_YU
int responseCode=httpConnection.getResponseCode(); %]2hxTV
if(responseCode>=400) $mV1K)ege
{ 907N;r
processErrorCode(responseCode); VDyQv^=#
return -2; //-2 represent access is error vSOO[.=
} NM`5hd{
wc%Wy|d
h2b,(
String sHeader; zXop@"(e
rY~!hZ
,#u"$Hz8p
for(int i=1;;i++) _DlX F
{ >;$C@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cILI%W1
//Utility.log(in.readLine()); _XO3ml\x@
sHeader=httpConnection.getHeaderFieldKey(i); j;GH|22
if(sHeader!=null) eVXlQO
{ ?>p(*
if(sHeader.equals("Content-Length")) &$1ifG
{ &^v5 x"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !R;NV|.eI6
break; O7M8!3Eqm
} ``zgw\f[%
} y*BS %xTF
else ?YeUA =[MC
break; &!xePKvO6k
} ko2T9NI:S
} W7F1o[
catch(IOException e){e.printStackTrace ();} $j+RUelFY
catch(Exception e){e.printStackTrace ();} mM[!g'*
BrHw02G
_VjfH2Y
Utility.log(nFileLength); )2tDX=D
u\jQe@j '
iOFp9i=j
return nFileLength; k3HPY}-
} pQ_EJX)
B#+0jdF;
o#D;H[' A
//保存下载信息（文件指针位置） K~C6dy
private void write_nPos() EO_:C9=d{
{ -KuC31s_W
try{ D<16m<b
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,esryFRG
output.writeInt(nStartPos.length); tRl01&0S
for(int i=0;i<nStartPos.length;i++) g+X .8>=
{ 2ncD,@ij
// output.writeLong(nPos); ~yGD("X
output.writeLong(fileSplitterFetch.nStartPos); #cnh ~O
output.writeLong(fileSplitterFetch.nEndPos); XTibx;yd<
} uPmK:9]3R
output.close(); gPW% *|D,
} [1LlzCAFBw
catch(IOException e){e.printStackTrace ();} x%hV5KW
catch(Exception e){e.printStackTrace ();} l"{1v~I
} u/I|<NAC,
XY_zFF
vhEqHjR:
//读取保存的下载信息（文件指针位置） 2`Ojw_$W7
private void read_nPos() ^n@dC?
{ 5~pQ$-
try{ !Qqi%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eTeZ^G
int nCount = input.readInt(); ef Moi'v
nStartPos = new long[nCount]; nT;Rwz$3
nEndPos = new long[nCount]; **D3.-0u&
for(int i=0;i<nStartPos.length;i++) Az`c? W%
{ UdiogXZ
nStartPos = input.readLong(); ,:E*Mw:
nEndPos = input.readLong(); \~(scz$
} mSg{0_:
input.close(); }Ai_peO0a
} uZg[PS=@!X
catch(IOException e){e.printStackTrace ();} ~l^Q~W-+
catch(Exception e){e.printStackTrace ();} I*SrKZb
} :rBPgrt
$ #*";b)QY
C8xxR~mq
private void processErrorCode(int nErrorCode) Mur)'
{ :j)v=qul
System.err.println("Error Code : " + nErrorCode); v7h!'U[/
} =hP7Hea(N
F=B[%4q`%
(/^s?`1{N?
//停止文件下载 ?f8)_t}^\
public void siteStop() *K57($F
{ TI<?h(*R_
bStop = true; mr6~8I
for(int i=0;i<nStartPos.length;i++) EZY <k#
fileSplitterFetch.splitterStop(); P,eP>55'K
FJ/c(K
-PG81F&K
} pz hPEp;
} kA"|PtrW
//负责部分文件的抓取 tQ@%3`
**FileSplitterFetch.java _oILZ,
*/ r'bPSu,
package NetFox; -5 Q gJ
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xpU7ZY
import java.io.*; TdCC,/c3
import java.net.*; B1U<m=Y
sU=7)*$
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public class FileSplitterFetch extends Thread { Zw`9B
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String sURL; //File URL Fmd^9K
long nStartPos; //File Snippet Start Position !1b4q/
long nEndPos; //File Snippet End Position 5fT"`FL?
int nThreadID; //Thread's ID auai@)v6
boolean bDownOver = false; //Downing is over [wO|P{8\"
boolean bStop = false; //Stop identical blk4@pg
FileAccessI fileAccessI = null; //File Access interface +W7#G `>
JQ~[$OGH
SJJ[y"GvD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "C/X#y
{ 7:S4 Ur
this.sURL = sURL; hHsN(v
this.nStartPos = nStart; X1C &;5
this.nEndPos = nEnd; 0XWhSrHM
nThreadID = id; mH,L,3R;R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m+a\NXWR?N
} l} =@9A@
v\3 \n3[u
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public void run() &*nq.l76X`
{ 1zP)~p3a
while(nStartPos < nEndPos && !bStop) 8{f~tPY
{ Gm.sl},
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b;5&V_
try{ Pe,:FIp,
URL url = new URL(sURL); 0|=,!sY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `mE>h4
httpConnection.setRequestProperty("User-Agent","NetFox"); K-2oSS56
String sProperty = "bytes="+nStartPos+"-"; DfsPg':z
httpConnection.setRequestProperty("RANGE",sProperty); QSNPraT
Utility.log(sProperty); QEQ/
)L0NX^jW;
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InputStream input = httpConnection.getInputStream(); [X7KlS9x2
//logResponseHead(httpConnection); %ZR<z$
gy*c$[NS$
!SPu9:
byte[] b = new byte[1024]; =A]*r9
int nRead; sd,KB+)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EZee kxs
{ |6O7_U#q
nStartPos += fileAccessI.write(b,0,nRead); NE)Yd7m-
//if(nThreadID == 1) 2CY4nSKW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &~K4I
} M?ObK#l!_
]5',`~jkF
8fSY@
Utility.log("Thread " + nThreadID + " is over!"); =MjkD)l
bDownOver = true; q\n,/#'i~
//nPos = fileAccessI.write (b,0,nRead); kc7,F2=F
} Kk\TW1w3
catch(Exception e){e.printStackTrace ();} f6])M)
} 8svN*`[
} oB$c-!&
\n<9R8g5
mFgrT
//打印回应的头信息 Z'!i"Jzq|{
public void logResponseHead(HttpURLConnection con) ?_t_rF(?6
{ R KXhD PA
for(int i=1;;i++) NyR,@n1
{ ^iqy|zNtn
String header=con.getHeaderFieldKey(i); |*%i]@V=
if(header!=null) \#sdN#e;XA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bamQ]>0|>!
Utility.log(header+" : "+con.getHeaderField(header)); _zK ~9/5
else Mc9JFzp
break; 1'YUK"i
} ?ocBRla
} QX+Xi<YE-
W QqOXF
2Bz\Tsp
public void splitterStop() @:Emmzucv|
{ < UD90}
bStop = true; re)7h$f}
} E"zC6iYZ;
k!"6mo@rd
[:gp_Z&
} ,v#O{ma
}B ?_>0
4Ifz-t/
/* `rest_vu
**FileAccess.java u\q(v D.
*//文件访问(定位，写) O~#A )d6
package NetFox; HV=P!v6
import java.io.*; _-|+k
&d_2WQ}
nIWY<Z"
public class FileAccessI implements Serializable{ )W/_2Q.
k![oJ.vHD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rtdEIk
RandomAccessFile oSavedFile; "BZL*hHq
long nPos; T,9pd;k
AD~_n^
~~3*o
public FileAccessI() throws IOException :(YFIW`59
{ 4YgO1}%G
this("",0); ~wQ M ?h
} 'Ll'8 ps
S.; ahce
Z.b?Jzj
public FileAccessI(String sName,long nPos) throws IOException W1JvLU5L*r
{ @:}la
oSavedFile = new RandomAccessFile(sName,"rw"); ?=,7'@e
this.nPos = nPos; TDX~?>P
oSavedFile.seek(nPos); +45.fo
} '?Xf(6o1
^fj30gw7\5
A_Y5{6@
public synchronized int write(byte[] b,int nStart,int nLen) Oe21noL
{ `Y3\R#
int n = -1; #y f
try{ &ZL4/e
oSavedFile.write(b,nStart,nLen); G2&,R{L6w
n = nLen; }yaM.+8.
} N, ,[V
catch(IOException e) 30YH}b#B
{ Ln8r~[tVE<
e.printStackTrace (); ]sI\.a
} \c1>15
bPIo9clq
9 ^=kt 2[
return n; QJSi|&Rx&?
} K{9
.I]EP-
%<|cWYM="z
} s_3a#I
!p Q*m`Xo
9&zQ5L>
/* sJMpF8
**SiteInfoBean.java WidLUv
*/ y!T8(
package NetFox; j_.tg7X
R5xV_;wD
MeYu
public class SiteInfoBean { %I;uqf
&79F Uac
>DAi-`e
private String sSiteURL; //Site's URL ]GDjR'[z
private String sFilePath; //Saved File's Path s@p:XO
private String sFileName; //Saved File's Name {I/t3.R`
private int nSplitter; //Count of Splited Downloading File "jf_xZ$H-
U#%+FLX@w
:jJ0 +Q
public SiteInfoBean() f?TS#jG4}
{//nSplitter的缺省值为5 ( j:eky
//default value of nSplitter is 5 &[ ,*
this("","","",5); dM-~Qo
} .LGA0
[<sN"
fNV-_^,R9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *;l[|
{ 7=s7dYlu
sSiteURL= sURL; -"I9`
sFilePath = sPath; 3_>=Cv}
sFileName = sName; CSH*^nk':O
this.nSplitter = nSpiltter; FD5OO;$
{{AZW
(C.aQ)|T
} Fzt7@VNxc
$-.*8*9
TPLv]$n
public String getSSiteURL() O)"Z%B
{ lYey7tl{
return sSiteURL; DPCQqV|7
} iba8G]2
4y!GFhMh
rxj#
public void setSSiteURL(String value) ND/oKM+?
{ cYBjsN(!A|
sSiteURL = value; 6!8uZ>u%Vg
} )@<HG$#
|{RCvm
9v1Snr
public String getSFilePath() {;Oj
{ 9m<%+S5&
return sFilePath; U;*O7K=P
} WXG0Z
s#(7D3Pr#
L* ScSxw
public void setSFilePath(String value) p.H`lbVY
{ IJC]Al,df
sFilePath = value; etQS&YzC
} bP,Ka
i^8w0H<-@v
/B|"<`-H
public String getSFileName() CAmIwAx6;
{ ff=RKKnN
return sFileName; k5*Z@a
} A|GsbRuy
,c 0]r;u!
_#uRKy<`N
public void setSFileName(String value) jUDE)~h
{ qIB2eCXw
sFileName = value; ,1]VY/
} \FF|b"E_=
",' Zr<T
V;Q@'<w
public int getNSplitter() @jq H8
{ fAfB.|cd
return nSplitter; rV2>;FG
} foB&H;A4oC
5DO}&%.xt
Vy^mEsQC+h
public void setNSplitter(int nCount) @1U6sQ
{ [z6P]eC7
nSplitter = nCount; Vt-V'`Y
} eu?P6>urA
} [{#n?BT
P.(z)!]
0DN&HMI#
/* t3C#$>
**Utility.java q^7=/d8
*/ 9$}>O]
package NetFox; :XTxrYt28
&Aym@G|k?
GaV OMT
public class Utility { .y0u"@iF
Yv2L0bUo:
>h~>7i(A
public Utility() wM#l`I
{ 3>=G-AH/$K
SpOSUpl%
%e_){28 n
} prB:E[1
8#4Gs Q"
//线程睡眠 um\A
public static void sleep(int nSecond) L`fT;2
{ }WF6w+
try{ bjN"H`Q
Thread.sleep(nSecond); t}MT<Jj
} )i\foSbB`V
catch(Exception e) \`%#SmQF
{ W .Al\!Gi
e.printStackTrace (); V8b^{}nxt
} 1^[]#N-Bu
} NxB/U_j
;=@?( n
//日志 ?%/*F<UVQ
public static void log(String sMsg) zy~*~;6tW
{ ^K 9jJS9K
System.err.println(sMsg); iR8;^C.aT
} (C%qA<6
t+jdV
3M'Y'Szm
public static void log(int sMsg) ej&o,gX
{ o=F!&]+
System.err.println(sMsg); <l>L8{-3
} E/D@;Ym18
} jO`L:D/C
vkW;qt}yO
'C;KNc
/* r4iT 9D
**TestMethod.java Jq+@%#G
*/ Ie8SPNY-H
package NetFox; EJJ&`,q
B*^QTJ
L:jv%;DM
public class TestMethod { F$9+WS`c
2%MS$Fto
|Z$)t%'
public TestMethod() J`wx72/-ZW
{ ///xx/weblogic60b2_win.exe U;gy4rj
try{ k_Lv\'Ok
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JqEo~]E]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .tK]-f2
SiteFileFetch fileFetch = new SiteFileFetch(bean); SK_N|X].
fileFetch.start(); 0,iG9D7
} ?:F Jc[J
catch(Exception e){e.printStackTrace ();} -NDB.~E^DJ
%*Yb J_j7
tcI Z 2H%
} ("=24R=a
Cio(Ptt:
t,kai6UM
public static void main(String[] args) *O-m:M!eA
{ nrM-\'
new TestMethod(); b'RBel;W
} 0iz\<' p
} !T}R=;)eh
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