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)); [ njx7d
} 8+"10q-
for(int i=0;i<nEndPos.length-1;i++) `#ul,%
{ k}D[Hp:m
nEndPos = nStartPos[i+1]; Ptx,2e&Hq
} 3brb*gI_b
nEndPos[nEndPos.length-1] = nFileLength; U/Wrh($ #4
} JWWYVl VC
} \PbvN\L
3?2<WEYr
thuRNYv<
//启动子线程 &|b4\uj9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )CLf;@1
for(int i=0;i<nStartPos.length;i++) y;nvR6)
{ r| f-_D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H?tUCbw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oV9z(!X/
nStartPos,nEndPos,i); :Hk_8J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $2KK:{VX
fileSplitterFetch.start(); >GXXjAIu/
} bKMWWJf*'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y7z(&M@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o)&"Rf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GRT]aw
nEndPos = " + nFileLength); 3pSj kS|?>
// fileSplitterFetch[nPos.length-1].start(); */w7?QOv
ydQ!4
;3;2h+U*
//等待子线程结束 CvK3H\.&;k
//int count = 0; qbiK^gR
//是否结束while循环 X4wH/q^
boolean breakWhile = false; (WRMaI72(
Fu7M0X'p
fN)x#?
while(!bStop) o@W_ai_
{ mu[Op*)
write_nPos(); nO{ x^b <
Utility.sleep(500); :g2 }C
breakWhile = true; (wuaxo:
*0y{ ~@
19Ww3PvQ;
for(int i=0;i<nStartPos.length;i++) zrRFn `B
{ XJgh>^R^
if(!fileSplitterFetch.bDownOver) ?^u^im
{ u7s"0f`
breakWhile = false; ?59'dGnz_
break; Zw{MgoJ0Z
} M0L&~p_F
} %2"J:0j
if(breakWhile) |sIr?RL{C
break; c~imE%
PLA#!$c7q
_c2WqQ-05
//count++; `G!M>h@
//if(count>4) j*400
// siteStop(); ^lj7(
} FW..mD9)}
3[d>&xk@$
@;iXp>&&
System.err.println("文件下载结束！"); 6L9,'Bg
} *k [J6
catch(Exception e){e.printStackTrace ();} &|9.}Z8U
} h2~4G)J
9b"MQ[B4#a
W.I\J<=V
//获得文件长度 ]Gv!M?:
public long getFileSize() C ^w)|2o}
{ ]$A(9Pn"
int nFileLength = -1; 9QwKakci
try{ l_{8+\`!
URL url = new URL(siteInfoBean.getSSiteURL()); /,s[#J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %m&@o~+
httpConnection.setRequestProperty("User-Agent","NetFox"); Sk}{E@
Kj3?ve~
G2:%g(
int responseCode=httpConnection.getResponseCode(); uw AwWgl
if(responseCode>=400) SA;#aj}rV
{ S($Su7g%_
processErrorCode(responseCode); ]:ZdV9`
return -2; //-2 represent access is error n,$z>
} Bv6K$4
o!c] (
ABh&X+YD
String sHeader; SaOYu &>
;dR=tAf0$Q
U{@5*4
for(int i=1;;i++) T,%j\0
{ pkgjTXR2b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _S}A=hK'
//Utility.log(in.readLine()); Jh&~ToF!
sHeader=httpConnection.getHeaderFieldKey(i); uXjP`/R|
if(sHeader!=null) QHq,/kWY
{ 2c5-)Dt)T
if(sHeader.equals("Content-Length")) tDg}Ys=4K>
{ k,yZ[n|`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O@V%Cu
break; #OO>rm$
} "A$!, PX6
} c0&Rg#
else qOih`dla
break; 4JGtI*%5lq
} BZ54*\t
} }7E^ZZ]f
catch(IOException e){e.printStackTrace ();} 9H-|FNz?c
catch(Exception e){e.printStackTrace ();} c2t=_aAIPQ
\R36w^c3
q@t0NvNSu
Utility.log(nFileLength); ^T"vX
y*pUlts<
!$-\;<bZw
return nFileLength; fC,:{}
} D=m'pL/pl
InXn%9]p]
ydRC1~f0
//保存下载信息（文件指针位置） bef_rH@`
private void write_nPos() ~T&<CTh
{ (q+)'H%iK
try{ ks$JP6
output = new DataOutputStream(new FileOutputStream(tmpFile)); |7yAX+
output.writeInt(nStartPos.length); 8V^oP]Y
for(int i=0;i<nStartPos.length;i++) ={K`4BD
{ EQ'V{PIfj
// output.writeLong(nPos); M`rl!Ci#
output.writeLong(fileSplitterFetch.nStartPos); 79`AM X[b
output.writeLong(fileSplitterFetch.nEndPos); R" ;xvo*
} QFYWA1<pDh
output.close(); 8!Vl
} +qh[N@F
catch(IOException e){e.printStackTrace ();} Tyvtmx M
catch(Exception e){e.printStackTrace ();} DxUKUE
} \,u_7y2 c
~//fN}~R
$s9Vrw0Z
//读取保存的下载信息（文件指针位置） tjupJ*Rt
private void read_nPos() e,t(q(L
{ UrqRx?#
try{ \v'p/G)g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0g0i4IV
int nCount = input.readInt(); c-B cA
nStartPos = new long[nCount]; =EHUR'
nEndPos = new long[nCount]; E[/\7v\
for(int i=0;i<nStartPos.length;i++) N<~t3/Nm
{ "rx-_uK*
nStartPos = input.readLong(); Y;?{|
nEndPos = input.readLong(); D9 g#Ff6
} eEuvl`&
input.close(); "wNJ
} r"P|dlV-
catch(IOException e){e.printStackTrace ();} WA+iYLx@H
catch(Exception e){e.printStackTrace ();} 3B84^>U<
} '.:z&gSqx0
ibj87K
< jJ
private void processErrorCode(int nErrorCode) Xu%'Z".>:
{ #qK:J;Sn3
System.err.println("Error Code : " + nErrorCode); C{U?0!^
} be.*#[
e)d`pQ6
jYk&/@`Ly
//停止文件下载 4 o Fel.o
public void siteStop() U/!TKic+
{ ?8'*,bK
bStop = true; Zy`m!]G]80
for(int i=0;i<nStartPos.length;i++) 8WXQOo8
fileSplitterFetch.splitterStop(); RoPRQCE
e|"WQ>
2LF/H$]o5
} KVclhT<F
} 4h|c<-`>t
//负责部分文件的抓取 V<GHpFi0
**FileSplitterFetch.java ItNz}4o|d
*/ r>>%2Z-P
package NetFox; 0XE4<U
l9{hq/V
~%&LTX0s|
import java.io.*; :D~DU,e'
import java.net.*; Y]'Z7<U}*E
*4\:8
TM%|'^)
public class FileSplitterFetch extends Thread { Fs9!S a7v
f6hnTbJ
0"<H;7K#W
String sURL; //File URL oB(?_No7
long nStartPos; //File Snippet Start Position gb[5&>(#
long nEndPos; //File Snippet End Position ?:Uv[|S#>
int nThreadID; //Thread's ID XP!S$Q]D
boolean bDownOver = false; //Downing is over A8muQuj]~~
boolean bStop = false; //Stop identical XO.jl"xu
FileAccessI fileAccessI = null; //File Access interface xQ7l~O b
rBQ_iB_
j'Fpjt"&=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &*M!lxDN
{ ` Fa~
this.sURL = sURL; $*^7iT4q_t
this.nStartPos = nStart; <}C oQz
this.nEndPos = nEnd; '$i: 2mn,
nThreadID = id; ?1~`*LE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 03$mYS_?
} R`NYEptJ
t%d Z-Ym
cuax;0{%
public void run() X8Bd3-B
{ h0g8*HY+}
while(nStartPos < nEndPos && !bStop) KI"#f$2&
{ l!D}3jD
~[t[y~Hup
zfJT,h-{
try{ b6,iZ+]
URL url = new URL(sURL); Z@4Arfl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `'DmDg
httpConnection.setRequestProperty("User-Agent","NetFox"); 5AFJC?
String sProperty = "bytes="+nStartPos+"-"; {&&z-^
httpConnection.setRequestProperty("RANGE",sProperty); ?g_3 [Fk
Utility.log(sProperty); ; 5*&xz
7r6.n61F
j\eI0b @*
InputStream input = httpConnection.getInputStream(); ">\?&0
//logResponseHead(httpConnection); {5Q!Y&N.%
E^B'4
L^1NY3=$
byte[] b = new byte[1024]; (>LF(ll
int nRead; ?tWaI{95I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Yj&F;_~
{ )v'WWwXY>
nStartPos += fileAccessI.write(b,0,nRead); 0_jf/an,%
//if(nThreadID == 1) \[;0KV_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )*$lp'~7N
} O%\*@4zM
fBU`k_
6_(&6]}66
Utility.log("Thread " + nThreadID + " is over!"); d-oMQGOklb
bDownOver = true; {a =#B)6
//nPos = fileAccessI.write (b,0,nRead); W_JlOc!y
} ld[I}88$
catch(Exception e){e.printStackTrace ();} a1T'x~ '
} #$.;'#u'so
} Kew@&j~
]=\].% >
H%[eV8
//打印回应的头信息 esJ~;~[@(r
public void logResponseHead(HttpURLConnection con) 0HZ{Y9]
{ !Lu2
for(int i=1;;i++) ]}V<*f
{ Pd8![Z3
String header=con.getHeaderFieldKey(i); 8=!D$t\3
if(header!=null) n*h)'8`Ut
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XgZD%7
Utility.log(header+" : "+con.getHeaderField(header)); 4j*
else u2tfF
break; lqy Qf$t
} 21n?=[
} v_yw@
t$`r4Lb9/
&j;wCvE4+
public void splitterStop() ez7A4>/
{ 2_>N/Z4T
bStop = true; {4l8}w
} 91/Q9xY
Q1Kfi8h}'
%7hrk
} Kf3"Wf^q
t^&Cxh
[:dY0r+
/* pd?Mf=>#
**FileAccess.java G0Iw-vf
*//文件访问(定位，写) )Om*@;r(
package NetFox; Ao 'l"-
import java.io.*; jVi) Efy
td$E/h=3
?4YGT
public class FileAccessI implements Serializable{ 5=-Q4d
_O?`@g?i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `>o{P/HN
RandomAccessFile oSavedFile; hDDn,uzpd
long nPos; J4hL_iCQ
fuW\bo3
3<Lx&p~%T
public FileAccessI() throws IOException 6XxvvMA97
{ y RqL9t
this("",0); 10Q ]67
} !aUs>1i
l]5KN
@FAA2d
public FileAccessI(String sName,long nPos) throws IOException N%@Qf~
{ -OV&Md:~
oSavedFile = new RandomAccessFile(sName,"rw"); gb1V~
this.nPos = nPos; 2Ah#<k-gC;
oSavedFile.seek(nPos); {p2!|A&a
} +|3@=.V
}dX*[I
j^*dmX
public synchronized int write(byte[] b,int nStart,int nLen) <sbu;dQ`
{ )$2QZ qX
int n = -1; hgG9m[?K
try{ M-VX;/&FR
oSavedFile.write(b,nStart,nLen); b`Zx!^
n = nLen; lf|FWqqV
} s S+MqBh&I
catch(IOException e) }rUN_.n4z
{ |"}FXaO
e.printStackTrace (); As&Sq-NWf
} h,:m~0gmj
bL`TySX
)MVz$h{c.]
return n; _;S-x
} >NV@R&
zaIKdI'/e
fUWG*o9
} ,Zx0%#6
z_$%-6
Y(ykng
/* 3DX*gsx(
**SiteInfoBean.java ^CYl\.Y@
*/ Qp5VP@t
package NetFox; ;+R&}[9,A)
:LQYo'@yB
ZDJ`qJ8V
public class SiteInfoBean { ,Fl)^Gl8?
gx/,)> E.
=ZznFVJ`={
private String sSiteURL; //Site's URL 2QcOR4_V
private String sFilePath; //Saved File's Path &J]K3w1p
private String sFileName; //Saved File's Name bSlF=jT[S
private int nSplitter; //Count of Splited Downloading File "]*&oQCI
lN)C2 2
z|J_b"u4
public SiteInfoBean() HVCe;eI
{//nSplitter的缺省值为5 ?=msH=N<l
//default value of nSplitter is 5 "S]0
this("","","",5); 9<?M8_
} W+c<2?d:
xj)F55e?
HyQJXw?A:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O/(`S<iip
{ }"H,h)T
sSiteURL= sURL; R%WCH?B<}
sFilePath = sPath; r|8d 4
sFileName = sName; k .;j
this.nSplitter = nSpiltter; xIW3={b3
sE<V5`Z=
$rBq"u=,0+
} x_}:D *aI
&|1<v<I5
76Cl\rV
public String getSSiteURL() 2zA4vZkbcw
{ *;slV3
return sSiteURL; M/'sl;
} O63<AY@
ZQsJL\x[UK
~W'{p
public void setSSiteURL(String value) 9L?.m&
{ 8 >EWKI9
sSiteURL = value; 2]jn '4
} XEp{VC@=
VcYrK4
%XDc,AR[
public String getSFilePath() y2dCEmhY
{ nNV'O(x}
return sFilePath; VA>35w
} 2#]#sZmk
c|y(2K)o[=
}OR@~V{Gj
public void setSFilePath(String value) H5B:;g@
{ A RuA<vQ
sFilePath = value; r'r%w#=`t
} 4jMFr,
(zYtNLoFx
6r0krbN
public String getSFileName() -UEZ#Q
{ 9';JXf$
return sFileName; CS5?Ti6
} +F` S>U
d#Y^>"|$.
X1|njJGO1
public void setSFileName(String value) DB|Y
{ m+R[#GE8#
sFileName = value; hGe/;@%
} BWa,f8
F?*-4I-
Ad8n<zt|
public int getNSplitter() ;>yxNGV`
{ L|:`^M+^w
return nSplitter; *[Tz![|
} u#$]?($}d
/QWvW=F2<
5E;qM|Ns
public void setNSplitter(int nCount) VcO0sa f`
{ cWsNr'MS*
nSplitter = nCount; ,X-bJA@(
} C.yQ=\U2
} +H-6eP
T|eu
9igiZmM
/* 4y?n [/M/
**Utility.java u(>^3PJ+
*/ L-WT]&n_
package NetFox; )._;~z!
z6=Z\P+
Oi'5ytsES
public class Utility { _[c0)2h
Nho>f
L^2%1GfE{
public Utility() #ym'AN
{ >V?eog%~
5y[Oj^
iDp)FQ$
} t7Iv?5]N
%KlrSo
//线程睡眠 x.!V^HQSN
public static void sleep(int nSecond) C=L>zOZ
{ v\gLWq'
try{ Bi3<7
Thread.sleep(nSecond); rNWw?_H-H(
} %9F([K
catch(Exception e) .+3g*Dv{&
{ ?W?c1>
e.printStackTrace (); df4A RP+
} F2LLN
} 6 l|DU7i
9k'7832u
//日志 30#s aGV
public static void log(String sMsg) 2^[`eg
{ TOB-aAO
System.err.println(sMsg); WYm\)@
} nLZTK&7}
UT~4x|b:O
[I,Z2G,Jb
public static void log(int sMsg) QC OM_$y
{ {tuYs:
System.err.println(sMsg); .Ni\\
} 1QcNp(MO
} dk#k bG;
+s,=lL
3=P]x;[ba
/* 6 6EV$*dRL
**TestMethod.java NqazpB*
*/ oi&VgnSk
package NetFox; HSE!x_$
+ZaSM~
~?Qe?hB
public class TestMethod { 9iIhte.
Z*]9E^
8yR.uMI$/
public TestMethod() <sGVR5NR
{ ///xx/weblogic60b2_win.exe K( c\wr\6
try{ ,i?nWlh+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D[[|")Fn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _/s$ZCd
SiteFileFetch fileFetch = new SiteFileFetch(bean); *MhRW,=
fileFetch.start(); 9X+V4xux
} wj$<t'MN
catch(Exception e){e.printStackTrace ();} ,*TmIPNK
q.^;!f1
In"ZIKaC
} 2+N]PW\V
b5dD/-Vj
7UKh688
public static void main(String[] args) O_muD\
{ njB;&N)I
new TestMethod(); oQ/E}Zk@
} #_ ;lf1x!
} "yy5F>0Wt
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