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)); THgzT\_zq
} `U_>{p&x
for(int i=0;i<nEndPos.length-1;i++) +Nbk\%
{ !otq X-
nEndPos = nStartPos[i+1]; W4*BR_H&*
} R9/xC7l@
nEndPos[nEndPos.length-1] = nFileLength; K}`p_)(
} hS{ *l9v7
} 8ex:OTzn|
y/I~x+y
4VJzs$
//启动子线程 2Lekckgv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "!Oh#Vf
for(int i=0;i<nStartPos.length;i++) DUKmwKM"k
{ UUf1T@-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aE+$&_>ef
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D2:a
nStartPos,nEndPos,i); *7;*@H*jd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J5p!-N`NS
fileSplitterFetch.start(); ,35:Srf|
} }0*ra37z>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sq(Ar(L<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E'S;4B5?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tW.>D;8
nEndPos = " + nFileLength); d)1sP0Z_@
// fileSplitterFetch[nPos.length-1].start(); 0 ,Qj:
y?z_^ppj
:.[5('
//等待子线程结束 p5;,/ |Ft
//int count = 0; w+9C/U;|s
//是否结束while循环 i?_D]BY4
boolean breakWhile = false; x]><}!\<&
zg Y*|{4Sl
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while(!bStop) qVD!/;l
{ @VC9gdO/
write_nPos(); f93rY<
Utility.sleep(500); %r
breakWhile = true; @EP{VV
.cT$h?+jyl
]7S7CVDk4
for(int i=0;i<nStartPos.length;i++) sJI-
{ ym*#ZE`B!
if(!fileSplitterFetch.bDownOver) Y0X94k.u
{ BdB`
breakWhile = false; Q`p}X&^a
break; dbT^9: Q
} }:9|*m<$t
} D0y,TF
if(breakWhile) fo\J \
break; ?Y6la.bc{
<x0uO
@7l=+`.i
//count++; zGL<m0C
//if(count>4) 2mG&@E
// siteStop(); iWN.3|r
} 9CK\tx&
E0)mI)RW.
G<u.+V
System.err.println("文件下载结束！"); *VC4s`<
} Hu9-<upc&
catch(Exception e){e.printStackTrace ();} sx(l
} z^!A/a[[!
fyg~KF}
&pMlt7
//获得文件长度 ??zABV
public long getFileSize() )-9w3W1r
{ mam5G!$
int nFileLength = -1; Ro'4/{}+
try{ ^I'Lw
URL url = new URL(siteInfoBean.getSSiteURL()); )>/j&>%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^tg6JB;s
httpConnection.setRequestProperty("User-Agent","NetFox"); d%_78nOh"
Qk~0a?#y5
$-fjrQ
int responseCode=httpConnection.getResponseCode(); ~Miin
if(responseCode>=400) {F(-s"1;xO
{ $O~F>.*
processErrorCode(responseCode); g3|Y$/J7P
return -2; //-2 represent access is error ^E<~zO=Z
} )0n29
#}t1
(J^Lqh_
String sHeader; (ju aDn)
q]iKz%|Z/
%KJhtd"q
for(int i=1;;i++) @q{:Oc^
{ 3vRLg b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #zSi/r/=1
//Utility.log(in.readLine()); 9#s95RO
sHeader=httpConnection.getHeaderFieldKey(i); >Oi2gPA
if(sHeader!=null) x<{;1F,k3
{ &w;^m/zP3
if(sHeader.equals("Content-Length")) 36^C0uNdX
{ 9&XV}I,~?|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h$aew63
break; VM<oUKh_3
} VeD+U~ d
} RP`GG+K
else i^yH?bH @~
break; n&YW".iG
} 0$f_or9T
} G&%nF4
catch(IOException e){e.printStackTrace ();} `u p-m=zA
catch(Exception e){e.printStackTrace ();} gc,J2B]61
y,y/PyN)
5Aa31"43n
Utility.log(nFileLength); `uNvFlP
*3.yumcv{L
I!F}`d
return nFileLength; ,Ou1!`6?t
} A"\P&kqMV
f74%YY
~C/Yv&58
//保存下载信息（文件指针位置） e_I; y
private void write_nPos() c#\ah}]Vo
{ oRT
try{ X ]pR,\B
output = new DataOutputStream(new FileOutputStream(tmpFile)); )8x:x7?
output.writeInt(nStartPos.length); .y %pGi
for(int i=0;i<nStartPos.length;i++) M9(ez7Z
{ Xc8= 2n
// output.writeLong(nPos); JK(`6qB>(6
output.writeLong(fileSplitterFetch.nStartPos); up+.@h{
output.writeLong(fileSplitterFetch.nEndPos); ?dJ/)3I%F
} zt)p`kdD
output.close(); V5e\%
} teq^xTUF[
catch(IOException e){e.printStackTrace ();} #514a(6
catch(Exception e){e.printStackTrace ();} ]ZR{D7.?
} P<cMP)+K
,<0Rf
RI[7M (
//读取保存的下载信息（文件指针位置） }J+ce
private void read_nPos() %jbJ6c
{ )){PBT}t]
try{ &jXca|wAR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 629~Uc6]
int nCount = input.readInt(); 9atjK4+o
nStartPos = new long[nCount]; Z;j/K
nEndPos = new long[nCount]; jy\W_CT
for(int i=0;i<nStartPos.length;i++) p|FlWR'mA
{ Eu`2w%qz
nStartPos = input.readLong(); 2y9:'c|
nEndPos = input.readLong(); T@K7DkP@
} w|!YoMk+o
input.close(); ^f^-.X
} KAj"p9hq+k
catch(IOException e){e.printStackTrace ();} _Hz~HoNU
catch(Exception e){e.printStackTrace ();} iwG>]:K3
} 3iu!6lC
L\/u}]dPQ
SWNU1x{,c\
private void processErrorCode(int nErrorCode) Fe_::NVvk
{ L?=#*4t
System.err.println("Error Code : " + nErrorCode); {f`lSu
} _L&n&y1+%
IZ4W_NN
ONjC(7
//停止文件下载 Ph(]?MG\_
public void siteStop() XysFwi
{ bDciZ7[b
bStop = true; m!HC-[<
for(int i=0;i<nStartPos.length;i++) ;,v!7
fileSplitterFetch.splitterStop(); s"I-YFP%c
_-4n~(
A|p@\3P*A
} }Kvh`@CiJ
} Nd]0ta
//负责部分文件的抓取 4)3g!o?
**FileSplitterFetch.java d u.HSXK
*/ Zw;$(="
package NetFox; EpRXjz
/~H[= Pf
/[\6oa
import java.io.*; r+imn&FK8
import java.net.*; g8%MOhg
=]=B}L`
fp.!VOy
public class FileSplitterFetch extends Thread { tP}Xhn`
Xtuhcdzu[
Hnfvo*6d.e
String sURL; //File URL I#i?**
long nStartPos; //File Snippet Start Position e%PCe9
long nEndPos; //File Snippet End Position *hv=~A $q
int nThreadID; //Thread's ID _oQtk^fp
boolean bDownOver = false; //Downing is over r/UYC"K3
boolean bStop = false; //Stop identical R'S c
FileAccessI fileAccessI = null; //File Access interface l\K%
Cr' !"F
UJ7'JBT=k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jK3giT
{ `)rg|~#k
this.sURL = sURL; L_tjcfVo
this.nStartPos = nStart; %)zk..K{l
this.nEndPos = nEnd; >pgQb9 T+_
nThreadID = id; IkSX\*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e{v,x1Y_z(
} pG)9=X!9
whV&qe;sw
gsW=3m&`
public void run() cDfx)sL
{ Lf5%M|o.)
while(nStartPos < nEndPos && !bStop) nVz5V%a!\q
{ \9046An
Zw2jezP@t
gE\A9L~b
try{ t[%x}0FP-F
URL url = new URL(sURL); ^$e0t;W=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /m97CC#+
httpConnection.setRequestProperty("User-Agent","NetFox"); q!ee g
String sProperty = "bytes="+nStartPos+"-"; MzG5u<D
httpConnection.setRequestProperty("RANGE",sProperty); A|2 <A !
Utility.log(sProperty); =Nw2;TkB[
P;j&kuW|zL
:lgHL3yl
InputStream input = httpConnection.getInputStream(); EC<5M5Lc
//logResponseHead(httpConnection); q_-ma_F#s
-<8B,
YkSuwx@5_q
byte[] b = new byte[1024]; ZH\0=l)
int nRead; nHrP>zN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :_>\DJ'>
{ KA`0g=
nStartPos += fileAccessI.write(b,0,nRead); \^Ep>Pq`]
//if(nThreadID == 1) 9X!ET!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $2Kau 1
} ~q*i;*
PoJmW^:}
-UJ?L
Utility.log("Thread " + nThreadID + " is over!"); 3voW
bDownOver = true; aD+0\I[x
//nPos = fileAccessI.write (b,0,nRead); z9^c]U U)E
} ~D*b3K8X
catch(Exception e){e.printStackTrace ();} <'W=]IAV
} ldK>HxM%Z
} f(!E!\&n^
&j3` )N
GaHA%
//打印回应的头信息 Ft3I>=f{
public void logResponseHead(HttpURLConnection con) BlL|s=dlQV
{ w2k<)3 g~
for(int i=1;;i++) -<xyC8$^$
{ P= e4lF.
String header=con.getHeaderFieldKey(i); 'c#IMlv
if(header!=null) ,E%1Uq"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mU>&ql?e
Utility.log(header+" : "+con.getHeaderField(header)); Jms=YLIAA
else Gv;;!sZ
break; Jff 79)f
} Bw6L;Vu
} ;xhOj<:
y">fN0{<
`n6/ A)
public void splitterStop() :"VujvFX
{ Tj&'KF8?L
bStop = true; #$FY+`
} n"iNKR>nW
CldDr<k3
Mxo6fn6-46
} h!v/s=8c
'5AvT: ^u
.?B{GnB>
/* l^ARW E
**FileAccess.java \9'!"-i
*//文件访问(定位，写) p'gb)nI
package NetFox; ?d4Boe0-a2
import java.io.*; NIaF5z
w(Gz({l+
kymn)Ea
public class FileAccessI implements Serializable{ `YU=~xQ
2yvVeo&3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &-=K:;x
RandomAccessFile oSavedFile; "NKf0F
long nPos; U~wjR"='
JIMWMk;ot
o*-9J2V=J
public FileAccessI() throws IOException -3` "E%9
{ N};t<Xev
this("",0); Hng!'
} 7D
#I;D
qcYNtEs*c
public FileAccessI(String sName,long nPos) throws IOException y+A{Y
{ tfA}`*$s
oSavedFile = new RandomAccessFile(sName,"rw"); %J _ymJ'pd
this.nPos = nPos; i|S:s
oSavedFile.seek(nPos); p0Gk j-
} +RS$5NLH
5KJ%]B(H2
e=7W7^"_
public synchronized int write(byte[] b,int nStart,int nLen) &+G;R
{ R]Ek}1~?
int n = -1; IM=+3W;ak
try{ %l]Rh/VPn?
oSavedFile.write(b,nStart,nLen); mB`D}g$
n = nLen; lufeieW
} lVoik*,B
catch(IOException e) ETO$9}x[
{ @(>XOj?+
e.printStackTrace (); [zQWyDu
} T9?54r
3 z=\.R
v,jhE9_O0
return n; =U"dPLax
} U<[jT=L
#uKWuGz]
H2U:@.o2&
} 3$_*N(e
7}%H2$Do
HxIoA
/* P6YQK+
**SiteInfoBean.java B?3juyB`--
*/ hVM2/j
package NetFox; Xu#:Fe}:
Xpl?g=B&u
Xm|ib%no
public class SiteInfoBean { ,9\Snn
K6B4sE
8teJ*sz
private String sSiteURL; //Site's URL .YR8v1Cp
private String sFilePath; //Saved File's Path ezn` _x_?
private String sFileName; //Saved File's Name $P nLG]X
private int nSplitter; //Count of Splited Downloading File 2+:'0Krc
,{8v4b-
OKAkl
public SiteInfoBean() [;^,CD|P
{//nSplitter的缺省值为5 =|,A%ZGF$
//default value of nSplitter is 5 =cn~BnowY
this("","","",5); ?Ht=[l=
} )Gb,^NGr
7@l<? (
="'- &
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DP*@dFU"
{ O%g\B8;
sSiteURL= sURL; [zh"x#AyI
sFilePath = sPath; %w5[*V
sFileName = sName; J +q|$K6
this.nSplitter = nSpiltter; YeyGN
lhO2'#]i
L/i(KF{
} ARWZ; GX
[/$N!2'5
RJ}#)cT
public String getSSiteURL() X;!~<~@Y
{ u7].}60.'
return sSiteURL; z"UPyW1?
} 1bSD,;$sQ
`R+,1"5=
[@G`Afaf
public void setSSiteURL(String value) "U8S81'
{ ^npJUa
sSiteURL = value; }C,O
} ;Z9IZ~
B4Lx{uno
,S!w'0k|n
public String getSFilePath() CW`!}yu%
{ f Iy]/
return sFilePath; >emcJVYV`[
} *||d\peQ
g_z/{1$
t&}6;z 3
public void setSFilePath(String value) y LM"+.?pL
{ }ZzLs/v%X
sFilePath = value; u|fXP)>.
} ]db@RbaH
kg>>D
o@k84+tn(
public String getSFileName() A5nO=
{ wa:0X)KC?
return sFileName; Nfn(Xn*J-
} Ik~1:D]f
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v}[dnG
public void setSFileName(String value) ZnfNQl[
{ n7l%gA*
sFileName = value; qSD9Pue
} 8l>CR#%@C
'~Q2!F
YI@Fhr &NU
public int getNSplitter() =SBBvnPLI
{ yPgmg@G@/
return nSplitter; ir[jCea,
} ,Z~;U
s9j7Psd
PDP[5q r
public void setNSplitter(int nCount) "A[ b rG
{ |d}MxS`^
nSplitter = nCount; 2UadV_s+s
} _MfD
} k \qiF|B)Z
e@n!x}t8
L?RF;jf
/* nE|@IGH
**Utility.java `xz&Scil
*/ \x+3f
package NetFox; tju|UhP3
&`!^Zq vG
aGoE,5
public class Utility { 7r 0,> 3"
;3m!:l
i8PuC^]
public Utility() N1x@-/xa|
{ d,cN(
'&yeQ
jbmTmh1q
} Y(6Sp'0
..<3%fL3
//线程睡眠 XL5Es:"+?S
public static void sleep(int nSecond) 0 f/.>1M=
{ %2l7Hmp4H
try{ uT_!'l$fr
Thread.sleep(nSecond); K@:m/Z}|4
} !GK$[9
catch(Exception e) ${hz e<g
{ p{Sh F.
e.printStackTrace (); ?mYYt]R
} K :LL_,
} J5yidymrpW
E4[}lX}
//日志 |$+5@+Zz
public static void log(String sMsg) *}!MOqP
{ '0t-]NAc
System.err.println(sMsg); [aqu}Su
} ,/,9j{|"j
:Vuf6,
& >JDPB?5
public static void log(int sMsg) :k,Q,B.I
{ .tXtcf/
System.err.println(sMsg); kQv*eZ~
} #AViM_u
} .dmi#%W
d"Q |I
xN"Z1n7t
/* r':TMhzHq?
**TestMethod.java :@3Wg3N
*/ @QEqB_W
package NetFox; 0pgY1i7
53OJ-m%a
V'gw\mcb
public class TestMethod { pchBvly+0
s(2GFc
*r,b=8|
public TestMethod() \fLvw
{ ///xx/weblogic60b2_win.exe r/:%}(7;
try{ 2>PH8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8cWZ"v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k|E]YvnfG
SiteFileFetch fileFetch = new SiteFileFetch(bean); &#m"/g7w4N
fileFetch.start(); uB.-t^@
} ^]c6RE_
catch(Exception e){e.printStackTrace ();} tj1JB%
` %?9=h%
,LYFEq_
} (9RslvKL
?Dsm~bkX[
n(;:*<Rh
public static void main(String[] args) mY&ud>,U:
{ -uR72f
new TestMethod(); jUMf6^^
} H{G{H=K_
} ]B4}eBt5)@
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