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)); L>~Tc
} .+u b\
for(int i=0;i<nEndPos.length-1;i++) 7?R600OA
{ dWQsC|
nEndPos = nStartPos[i+1]; GKo&?Tj)
} o:Kw<z,$H
nEndPos[nEndPos.length-1] = nFileLength; -&Xv,:'?
} IyHbl_P ^
} m4@NW*G{
-:ucp2
*KvD$(ny
//启动子线程 c$ZVvu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -sQ[f18
for(int i=0;i<nStartPos.length;i++) *"w hup[
{ 4l ZK@3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0i_:J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), klJ21j0Bb2
nStartPos,nEndPos,i); rT[qh+KWe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2.z-&lFBZ
fileSplitterFetch.start(); Ll|_Wd.K,
} `?Q p>t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (|^m9v0:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b&F9<XLqq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &kIeW;X
nEndPos = " + nFileLength); VGQ~~U7}@
// fileSplitterFetch[nPos.length-1].start(); @Iz]:@\cJ
hNN[djR
/dYv@OU?
//等待子线程结束 p@G7}'|eyA
//int count = 0; nU_O|l9
//是否结束while循环 5&n{QE?Um
boolean breakWhile = false; OtqFI!ns
{3`385
4=tR_s
while(!bStop) 'vBZh1`p
{ $].htm
write_nPos(); D|9+:Y
Utility.sleep(500); *(Dmd$|0|
breakWhile = true; qazA,|L!
+\Vm t[v
RHC ZP
for(int i=0;i<nStartPos.length;i++) mF*x&^ie
{ ~+dps i
if(!fileSplitterFetch.bDownOver) ?+d`_/IB
{ U0_^6zd_
breakWhile = false; 06pvI}
break; _Ub `\ytx
} !e|\1v'0
} !B3TLeh
if(breakWhile) R(~wSL*R>
break; H\S)a FY[
lDYgtUKG
[7v|bd
//count++; 5^Qa8yA>7
//if(count>4) !y_{mE?V(
// siteStop(); |Ghk8 WA
} Q6Gw!!Z5EA
zi-_l
#Lhv=0op
System.err.println("文件下载结束！"); G|g^yaq>
} nQc#AFg
catch(Exception e){e.printStackTrace ();} @yuiNj.T
} p:4jY|q
h+[6i{
O_:l;D#i
//获得文件长度 _nbr%PD,
public long getFileSize() aZA``#p+
{ ]1!" q40)]
int nFileLength = -1; 3%Y:+%VE
try{ @z@%vr=vX
URL url = new URL(siteInfoBean.getSSiteURL()); D!&(#Vl _
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P"vrYom
httpConnection.setRequestProperty("User-Agent","NetFox"); 3xChik{
=j,WQ66r3
F[jE#M=k
int responseCode=httpConnection.getResponseCode(); ,L/x\_28
if(responseCode>=400) |u&cN-}C d
{ iQ/~?'PB
processErrorCode(responseCode); +"?+Be
return -2; //-2 represent access is error o <q*3L5
} 7PY$=L48A
2zTi/&K&
<sH}X$/
String sHeader; !$Nj!
#V!a<w4_
K!-OUm5A
for(int i=1;;i++) X$Vi=fvt
{ fW-C`x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ShB]U5b:k
//Utility.log(in.readLine()); .;?!I_`
sHeader=httpConnection.getHeaderFieldKey(i); jo`ZuN{
if(sHeader!=null) _VrY7Mz:r
{ PXb$]HV
if(sHeader.equals("Content-Length")) iEvQ4S6tD
{ U[C4!k:0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Mkz_.;3
break; V_+&Y$msi~
} u7!9H<{>P
} cSb;a\el$
else ywa*?3?c
break; ot^pxun
} vQMBJ&
} {D+mr[ %
catch(IOException e){e.printStackTrace ();} _Iy\,<
catch(Exception e){e.printStackTrace ();} |YJ83nSO~
_;1{feR_
iod%YjZu
Utility.log(nFileLength); H71sxek3
cr1x CPJj
7zM:z,
return nFileLength; m@4Dz|
} fj_23{,/"g
/at7H!
S#/%#k103
//保存下载信息（文件指针位置） `AJ[g>py^|
private void write_nPos() b^1QyX^?:
{ eVXXn)>
try{ C 0w+ j
output = new DataOutputStream(new FileOutputStream(tmpFile)); TQa}Ps
output.writeInt(nStartPos.length); VeoG[Jl
for(int i=0;i<nStartPos.length;i++) ~^mUu`@r
{ `Fy-"Uf
// output.writeLong(nPos); xnP!P2
output.writeLong(fileSplitterFetch.nStartPos); ^jdU4
output.writeLong(fileSplitterFetch.nEndPos); t^rw@$"}
} )Z}AhX
output.close(); >yBqi^aL
} 9j,g&G.K
catch(IOException e){e.printStackTrace ();} n>M`wF>
catch(Exception e){e.printStackTrace ();} GtA`0B
} h!EA;2yGKa
tq3Wga!5
}r,\0Wm
//读取保存的下载信息（文件指针位置） 4.RQ3SoDa
private void read_nPos() zKJ2~=
{ BrV{X&>[i
try{ Z~5) )5Ye;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xUo6~9s7
int nCount = input.readInt(); k:@DK9 "^
nStartPos = new long[nCount]; $<}c[Nm
nEndPos = new long[nCount]; #~u0R>=
for(int i=0;i<nStartPos.length;i++) LFp "Waiv
{ +{J8,^z#
nStartPos = input.readLong(); )-C3z
nEndPos = input.readLong(); NTg@UT<
} IrLGAQ0
input.close(); qL(Q1O!
} }r:o8+4
catch(IOException e){e.printStackTrace ();} zZ5:)YiW-
catch(Exception e){e.printStackTrace ();} ep0,4!#FAO
} !IxO''4
NxT"A)u
[|}IS@
private void processErrorCode(int nErrorCode) C*7/iRe
{ {z#2gc'Q
System.err.println("Error Code : " + nErrorCode); #/)t]&n
} "}4%vZz
1yy?1&88S
i|YS>Pw~j
//停止文件下载 mgs(n5V5
public void siteStop() xO~ElzGm
{ jlEz]@ i
bStop = true; ()3\(d5e
for(int i=0;i<nStartPos.length;i++) N##`
fileSplitterFetch.splitterStop(); wj|Zn+{"nF
,"(L2+Yp
?6#won
} sDY~jP[Oa
} IK~&`n](>
//负责部分文件的抓取 [6/QUD8
**FileSplitterFetch.java -N *L1Zj
*/ EY}:aur
package NetFox; em$pU*`P
#YUaM<O
1<@SMcj>
import java.io.*; W U(_N*a
import java.net.*; E8Dh;j
yU?jmJ
; * [:~5Wc
public class FileSplitterFetch extends Thread { ~/ %Xm<
s\ IKSoE
=bVPHrKNQ
String sURL; //File URL G dgL}"*F
long nStartPos; //File Snippet Start Position 2z.ot'
long nEndPos; //File Snippet End Position Hvl n>x@
int nThreadID; //Thread's ID Wboh2:TH:
boolean bDownOver = false; //Downing is over k4TWfl^}9
boolean bStop = false; //Stop identical 0c_xPBbB+
FileAccessI fileAccessI = null; //File Access interface I`>U#x*
v9$!v^U"D
]BQYVx/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r-2k<#^r
{ {7o#Ve
this.sURL = sURL; ab0Sx
this.nStartPos = nStart; gT+/nSrLV
this.nEndPos = nEnd; enoj4g7em^
nThreadID = id; i;[y!U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a QH6akH
} gr=h!'m
%x)bZ=An
+2tQFV;
public void run() z\YIwrq3*
{ +^)v"@,VP
while(nStartPos < nEndPos && !bStop) /@os*c|je
{ +SJ.BmT
{K(mfTqm
IG-\&
try{ 5pO|^Gj1
URL url = new URL(sURL); X1L@ G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K%^n.
httpConnection.setRequestProperty("User-Agent","NetFox"); BHXi g~d
String sProperty = "bytes="+nStartPos+"-"; OWd'z1Yl
httpConnection.setRequestProperty("RANGE",sProperty); GkIE;7#2kX
Utility.log(sProperty); v gN!9
!>UlvT-
{Gxe%gu6K
InputStream input = httpConnection.getInputStream(); /--p#Gh'
//logResponseHead(httpConnection); g(7-3q8eq
\-<BUG]=
c:[k+_Zr
byte[] b = new byte[1024]; h}bfZL
int nRead; E?m~DYnU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q76POytV|
{ 'CLZ7pV
nStartPos += fileAccessI.write(b,0,nRead); ;C]Ufk
//if(nThreadID == 1) h}b:-a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xNz(LZ.c
} 1MelHW
v=`yfCX-qX
x2"iZzQlD
Utility.log("Thread " + nThreadID + " is over!"); 8:cbr/F<
bDownOver = true; H=dIZ
//nPos = fileAccessI.write (b,0,nRead); ?^|`A}q#
} 18g_v"6o
catch(Exception e){e.printStackTrace ();} :_{8amO
} Cu"Cpt[
} .UyE|t4
HL)!p8UHJ
DA=!AK>
//打印回应的头信息 ~lj~]j
public void logResponseHead(HttpURLConnection con) 0D-`>_
{ A_9WSXR
for(int i=1;;i++) f~IJ4T2#N
{ 3;nOm =I
String header=con.getHeaderFieldKey(i); @sXFu[!U
if(header!=null) _1" ecaA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9hp&HL)BOa
Utility.log(header+" : "+con.getHeaderField(header)); yTm \OUD
else U'jt'(
break; .RQra+up
} RNIXQns-=S
} jnH\}IB
XxqGsGx4
<}a?<):S
public void splitterStop() +X?ErQm
{ ~ELY$G.xl
bStop = true; Gvb2>ZN
} XN<SKW(H3
K+g[E<x\=
X-pbSq~5
} [g}Cve#i
_0H oJ
UBvp32p
/* i,Ct AbMx
**FileAccess.java !\4x{Wa]
*//文件访问(定位，写) c{#2;k Q,
package NetFox; $ {yct
import java.io.*; =bKDD<(
R|;BO:S1
>KKWhJ
public class FileAccessI implements Serializable{ mvn- QP~"
(f/(q-7VWt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -YoL.`s1
RandomAccessFile oSavedFile; )|gw5N4;
long nPos; ^'UM@dd?!
N['DqS =
43=v2P0=Tj
public FileAccessI() throws IOException !pU$'1D
{ fI.|QD*$b
this("",0); Y2|i>5/|<
} 9#8vPjXW}.
<T2O^
x6ghO-s
public FileAccessI(String sName,long nPos) throws IOException !V|{(>+<
{ (m]l -Re
oSavedFile = new RandomAccessFile(sName,"rw"); .#EU@Hc
this.nPos = nPos; \S}/2]* 1
oSavedFile.seek(nPos); 4,RPidv%O
} E^8|xT'h6
)e(<YST
A;AQw
public synchronized int write(byte[] b,int nStart,int nLen) mxNd
{ x#{!hL 5G
int n = -1; LI,wSTVjC
try{ ~Xi@#s~
oSavedFile.write(b,nStart,nLen); 1M ?BSH{
n = nLen; -cqE^qAdX
} z?/_b
catch(IOException e) K3&xe(
{ x}G:n[B7_V
e.printStackTrace (); qs4jUm
} r@G*Fx8Z
8ud12^s$
?sfqg gi
return n; O&!R7T
} &raqrY|V
3%vXB=>T!
l9K`+c+t
} ZL|aB886
wMS%/l0p1
]n^iG7aB?
/* xoZm,Pxd
**SiteInfoBean.java ~nZcA^b#DQ
*/ IjI'Hx
package NetFox; !do`OEQKR
KEAXDF&#
dx%z9[8~{.
public class SiteInfoBean { 4o>y9
\gA!)q.;
~^wSwd[
private String sSiteURL; //Site's URL :saP :&
private String sFilePath; //Saved File's Path W>3S%2d
private String sFileName; //Saved File's Name mK:gj&N7X|
private int nSplitter; //Count of Splited Downloading File ^PG"
O9ex=m `L
0`/G(ukO
public SiteInfoBean() ,dC.|P' `
{//nSplitter的缺省值为5 zt.kNb
//default value of nSplitter is 5 OqtGKda
this("","","",5); ^*.[b
} Ai/X*y:[?
j~v`q5X
@SX%q&-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ak[X`e T
{ {FIzoR"
sSiteURL= sURL; )uqzu%T
sFilePath = sPath; sXVl4!=l6
sFileName = sName; \Vc[/Qp7Bb
this.nSplitter = nSpiltter; rr#nBhh8
9r%fBiSk
<':h/d
} }`R,C~-|^
uq5?t
4`O[U#?
public String getSSiteURL() w>W#cTt
{ 20Zxv!
return sSiteURL; <AgB"y@
} ZP";B^J
<83Ky;ry
WNR]GI
public void setSSiteURL(String value) vF\>;pcT
{ O_QDjxj^rZ
sSiteURL = value; ,gV#x7IW
} *aErwGLB8
.W]k8N E
l!ow\ZuQBF
public String getSFilePath() BN*:*cmUl
{ Vh-8pFt
return sFilePath; HT<p=o'$Z
} x`E<]z*w}
mTe3%( LD
sx?IIFF
public void setSFilePath(String value) - 2)k!5X=
{ pRQ7rT',v
sFilePath = value; TV{GHB!p"
} BTAbDyH5
k>&cHCS`*
=.`\V]
public String getSFileName() 7@@g|l]
{ gvP-doA7W
return sFileName; N~/'EaO
} z;JV3)E
M?l v
bjVk9XvH6
public void setSFileName(String value) @a9.s
{ bi8_5I[
sFileName = value; qU26i"GHp
} 1!uBzO6/$
(xgw';g
?]><#[?'L
public int getNSplitter() Pmv@
{ BX/3{5Y>{
return nSplitter; ,Zmjw@w
} )N 3^r>(e<
AJyNlQ
|z)s9B;:#i
public void setNSplitter(int nCount) W.3b]zcV
{ x-i1:W9;
nSplitter = nCount; [8T{=+k
} Y`~B> J
} ]I|(/+}M
izP)t
C0N :z.)4
/* L:HvrB~
**Utility.java (zsG!v
*/ J~%43!X\K
package NetFox; L[<#>/NPy
;6/WjUDw<|
m>=DJ{KQ
public class Utility { !hVbx#bXl
oC`F1!SfOO
:M(uP e=D
public Utility() Sp>g77@
{ A8f.h5~9
[9 MH"\
<vcU5 .K.
} FKO2UY#&7
`D;*.zrA
//线程睡眠 oU|G74e6
public static void sleep(int nSecond) V'9.l6l
{ }Xj25` x
try{ ,X4b~)
Thread.sleep(nSecond); +2`BZ}5y
} PC9,;T&7_
catch(Exception e) ~| j eNT
{ Q:b0M11QR
e.printStackTrace (); ?^voA.Bv<
} d,GOP_N8I
} "3^tVX%$\[
9FDu{4:
//日志 vRe{B7}p;
public static void log(String sMsg) |gE1P/%k
{ lcl|o3yQ
System.err.println(sMsg); hDxq9EF
} Au,oX2$
/\%<VBx ?q
rZ?:$],U!
public static void log(int sMsg) JpS}X\]i
{ JP4DV=}L
System.err.println(sMsg); 6*i**
} G _cJI
} F*P0=DD
^;EhKG
$Ivjcs:
/* 8m") )i-
**TestMethod.java gGMfy]]R
*/ 6+$2rS$1V
package NetFox; Jk*cuf`rq
Uxjc&o
-leX|U}k
public class TestMethod { Q]9$dr=Kk0
?4':~;~
CyIlv0fd}
public TestMethod() FMdu30JV
{ ///xx/weblogic60b2_win.exe !AwMD
try{ uG\~Hxqw7O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x*Z'i<;B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `n$Ak5f
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z1 Nep!
fileFetch.start(); &vrQ *jX
} s70Z&3A
catch(Exception e){e.printStackTrace ();} wsmgkg
HAn{^8"@
IQJ"B6U)
} [NSslVr
<IR#W$[
e(7#>O%1
public static void main(String[] args) u+V*U5v
{ *X.1b!
new TestMethod(); [Vs\r&qL
} iaL@- dg
} ~YH?wdT
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