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)); nf 8V:y4
} FrXP"U}Y
for(int i=0;i<nEndPos.length-1;i++) qfE0J;e
{ cVL|kYVWT
nEndPos = nStartPos[i+1]; |zpy!X3
} *0!p_Hco
nEndPos[nEndPos.length-1] = nFileLength; Hf]:mhH
} 9AX}V6\+
} u5k{.&
L4m Vk
4i)5=H
//启动子线程 Jp]?tlT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KxX[8
for(int i=0;i<nStartPos.length;i++) yef\Y3X
{ U,EoCAm>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C:t>u..
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o&E8<e
nStartPos,nEndPos,i); 9Sxr9FLW~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e>Z&0lV:
fileSplitterFetch.start(); 06f%{mAZS
} w>^(w<~Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B=a+cT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -|#{V.G3'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _) x{TnK
nEndPos = " + nFileLength); qsep9z.
// fileSplitterFetch[nPos.length-1].start(); Mu[lk=jC
znsQ/[
KQNQ<OE4
//等待子线程结束 9efey? z
//int count = 0; y%i9 b&gDd
//是否结束while循环 ITw *m3
boolean breakWhile = false; .))jR:{3
qS/}aDk&
j*?8w(!
while(!bStop) Jq&Hz$L|
{ ,Zn6T"[$
write_nPos(); H%vfRl3rB
Utility.sleep(500); >S7t
breakWhile = true; k;+TN9
h8`On/Ur_8
M=liG+d
for(int i=0;i<nStartPos.length;i++) K'Ywv@
{ *HR pbe2
if(!fileSplitterFetch.bDownOver) ?K[Y"*y2
{ ay7\Ae]
breakWhile = false; )Ri!
break; Lxp}o7>K
} GLtWo+g0
} {q)d
if(breakWhile) H_RfIX)X
break; iN Oj@3x
w<`0D)mQ
I2$DlEke
//count++; \ T#|<=
//if(count>4) K`Kv.4
// siteStop(); .8|wc
} 6 H P66B
6v3l^~kc'
M/p9 I gp
System.err.println("文件下载结束！"); ?0/$RpFEM#
} x!_5/
catch(Exception e){e.printStackTrace ();} $UH:r
} y<FC7
2@ZVEN
Nz2VaZ
//获得文件长度 47Z3nl?
public long getFileSize() (2#Xa,pb
{ #s~;ss ,
int nFileLength = -1; #]jl{K\f#X
try{ ,6{z
URL url = new URL(siteInfoBean.getSSiteURL()); MWv@]P_0p!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a -Pz<*
httpConnection.setRequestProperty("User-Agent","NetFox"); -13}]Gls7Q
9-T<gYl
>XgJo7u
int responseCode=httpConnection.getResponseCode(); e n~m)r3&
if(responseCode>=400) Sxq@W8W
{ ck{S
processErrorCode(responseCode); }?,?2U,8:
return -2; //-2 represent access is error Q^f{H.
} 4}m9,
$~b6H]"9
i`gM> q&
String sHeader; <4Gy~?
Nf)YG!
lwf4ke
for(int i=1;;i++) ^_ch%3}Im
{ GFdbwn5B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -fPiHKJ
//Utility.log(in.readLine()); 3UUdJh<~
sHeader=httpConnection.getHeaderFieldKey(i); \:J=tAC
if(sHeader!=null) c},pu[nL
{ 5FR#CQ
if(sHeader.equals("Content-Length")) x9Z89Gwi
{ ;|vP|Xi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3Qe|'E,U
break; P'qBqx[
} L6_%SGY_iE
} `Qo37B2
else t\ oud{Cv
break; I%J>~=]n_
} qqw P4ceG
} ,kJ7c;:i
catch(IOException e){e.printStackTrace ();} ar<8wq<4G
catch(Exception e){e.printStackTrace ();} CKn2ZL
_dm0*T ?
&qS%~h%2
Utility.log(nFileLength); F^gTID
BjfVNF;hk:
E_=F'sP?
return nFileLength; $97O7j@
} /8e}c`
.1[.f}g$J
'{2]:
//保存下载信息（文件指针位置） S&}7XjY
private void write_nPos() {d[Nc,AMb
{ g}0K@z3
try{ @\&j3A
output = new DataOutputStream(new FileOutputStream(tmpFile)); $"vz>SuB
output.writeInt(nStartPos.length); .+1I>L
for(int i=0;i<nStartPos.length;i++) #sc!H4
{ !*:g??[T
// output.writeLong(nPos); 62HA[cr&)
output.writeLong(fileSplitterFetch.nStartPos); 06]3+s{{
output.writeLong(fileSplitterFetch.nEndPos); E'aOHSAg
} X\Bl? F
output.close(); |s! _;6
} ^Q`5+
catch(IOException e){e.printStackTrace ();} qt@/
catch(Exception e){e.printStackTrace ();} +4%~.,<_to
} L-w3A:jk
!s-A`} s+
ndLEIqOY
//读取保存的下载信息（文件指针位置） ,RR{Y-
private void read_nPos() p*c(dkOe8
{ by>%}#M
try{ &AJ bx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y|LL]@Lv
int nCount = input.readInt(); k";dK*hD,
nStartPos = new long[nCount]; O z0-cM8t
nEndPos = new long[nCount]; H*N<7#
for(int i=0;i<nStartPos.length;i++) P6GTgQ<'BA
{ ,pD sU@
nStartPos = input.readLong(); `'s_5Ek
nEndPos = input.readLong(); DYf2V6'
} !tTv$L>
input.close(); ~frsgHW
} &'/"=lK
catch(IOException e){e.printStackTrace ();} }9\_s*
catch(Exception e){e.printStackTrace ();} O6Py
} 5&s6(?,Eu
ura&9~
p"hO6b%V
private void processErrorCode(int nErrorCode) tAN!LI+w
{ c]Epg)E
System.err.println("Error Code : " + nErrorCode); f DXK<v)
} F)cCaE;
Hy3J2p9.
^rJTlh 9
//停止文件下载 &pzL}/u
public void siteStop() )L9eLxI
{ <}WSYK,zUY
bStop = true; IaeO0\ 4E
for(int i=0;i<nStartPos.length;i++) *}89.kCBF
fileSplitterFetch.splitterStop(); w0g@ <( 3
v>LK+|U
_\d|`3RM
} @FIL4sb
} =Oy&f:s
//负责部分文件的抓取 ?Vg~7Eu0
**FileSplitterFetch.java fSbLkd 9
*/ &$|~",
package NetFox; >;Hx<FKxP
(X@\2M4@T#
legWY)4D;
import java.io.*; b~&cYk'
import java.net.*; 5Yv*f:
D 1.59mHsD
68?&`/t
public class FileSplitterFetch extends Thread { R_G2C@y*
1K3XNHF
,mm97I
String sURL; //File URL -E\G3/*51
long nStartPos; //File Snippet Start Position /rZk^/'
long nEndPos; //File Snippet End Position /4Wf\ Zu
int nThreadID; //Thread's ID $EY[CA E
boolean bDownOver = false; //Downing is over Xi"9y @
boolean bStop = false; //Stop identical &C MBTY#u
FileAccessI fileAccessI = null; //File Access interface qWW\d', .
A~Sc ] M
3Y#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |5(un#
{ UhW{KIW
this.sURL = sURL; KOe]JDU
this.nStartPos = nStart; =*'yGB[x)
this.nEndPos = nEnd; ;cf$u}+
nThreadID = id; !y_L~81?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )>h3IR
} )*}\fmOv{
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public void run() =T3{!\tH
{ ?x",VA
while(nStartPos < nEndPos && !bStop) BywEoS
{ G h+;Vrx
\ R}I4'
$DH/
try{ U $#^ e
URL url = new URL(sURL); 2#$7!`6K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H 2I
httpConnection.setRequestProperty("User-Agent","NetFox"); x(u.(:V
String sProperty = "bytes="+nStartPos+"-"; kq=Htbv7
httpConnection.setRequestProperty("RANGE",sProperty); t'Yd+FK
Utility.log(sProperty); H$ nzyooh
N_:!uR
Lfx a^0
InputStream input = httpConnection.getInputStream(); e6'0g=Y#
//logResponseHead(httpConnection); W= NX$=il
EUt2S_2P
z}J~X%}e
byte[] b = new byte[1024]; ])y)]H#{
int nRead; ^) s6`:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #(qvhoi7lM
{ br88b`L
nStartPos += fileAccessI.write(b,0,nRead); :@&e~QP(
//if(nThreadID == 1) 2A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @8J*vY =e
} G?F!Z"S
X_-/j.
IrRy1][Qr
Utility.log("Thread " + nThreadID + " is over!"); "T /$K
bDownOver = true; &O+S[~
//nPos = fileAccessI.write (b,0,nRead); |b@`ykD
} /b{@']
catch(Exception e){e.printStackTrace ();} #pRbRT9
} ~Fvz&dO
} 3U?gw!M>
"=]'"'B:
0KExB{K
//打印回应的头信息 )]Zdaw)X
public void logResponseHead(HttpURLConnection con) SKf;Fe
{ Wx/PD=Sf&
for(int i=1;;i++) *9KT@"v
{ H '5zl^8I
String header=con.getHeaderFieldKey(i); g#{7qmM
if(header!=null) $n8&5<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KDg%sgRu}
Utility.log(header+" : "+con.getHeaderField(header)); /FXb,)1t
else 1h(n}u
break; &gV9h>Kc#
} `Q+O#l?
} 0p3) t
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hT=E~|O
public void splitterStop() O:V.;q2]U
{ *W |
bStop = true; Q.4+"JoG
} 7zQGuGo(
l66 QgPA
/FTP8XHwL)
} mtFC H
meB9:w[m
#?M[Q:
/* p/ZgzHyF
**FileAccess.java Y]&2E/oc
*//文件访问(定位，写) A\/DAVnI
package NetFox; IwXQbJ3v_
import java.io.*; )q!dMZ(
vG}\Amx+
4nd)*0{f
public class FileAccessI implements Serializable{ >PWDo
:`yW^b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !=vsY]
RandomAccessFile oSavedFile; KdlUa^}D
long nPos; %MtaWZ
!Y^B{bh
bneP>Bd
public FileAccessI() throws IOException 5 a&a-(
{ K#v@bu:'
this("",0); hNcEBSQ
} l0!`>Xx[b
!9C]Fs*`?
B&3@b
public FileAccessI(String sName,long nPos) throws IOException 7'{%djL
{ 3gCP?%R
oSavedFile = new RandomAccessFile(sName,"rw"); Kv5 !cll5
this.nPos = nPos; #B$_ily)
oSavedFile.seek(nPos); X=Y>9
} ]nS9taEA
I*+*Wf
oXwcil
public synchronized int write(byte[] b,int nStart,int nLen) 0ZAtBq.s
{ \o?
int n = -1; )Zyw^KN^
try{ &~)1mnv.
oSavedFile.write(b,nStart,nLen); k V'0rb
n = nLen; z\J#d 1e
} &C/,~pJ1S
catch(IOException e) Ip,0C8T`Q
{ K]U8y$^
e.printStackTrace (); tdi}P/x
} vf<Tq
AIQ]lQ(
TY#pj
return n; qy!pD R;
} fJ-8$w\uL
t2-bw6U
6~Zq
} y5V]uQSD
]\=M$:,RZ
8{.:$T
/* {M0pq3SL*t
**SiteInfoBean.java uc;,JX!bN
*/ X2('@Yh
package NetFox; =H^^AG\}
mhnK{M @56
W-"FRTI4
public class SiteInfoBean { P4"EvdV7
`{@?O%UB
>\ym{@+*
private String sSiteURL; //Site's URL pc_$,RkN
private String sFilePath; //Saved File's Path A$'rT|>se
private String sFileName; //Saved File's Name 9TE-'R@
private int nSplitter; //Count of Splited Downloading File IPh_QE2g
FU(s jB
~gbq^
public SiteInfoBean() ZsDn`8
{//nSplitter的缺省值为5 (/_Z^m9
//default value of nSplitter is 5 X?]1/6rV
this("","","",5); /aMeKM[L`
} TCO^9RP<
"IsDL^)A9
"(y|iS$^T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A!5)$>!o
{ 5zII4ukn*
sSiteURL= sURL; b"#|0d0
sFilePath = sPath; )x&}{k6 %
sFileName = sName; e0u*\b
this.nSplitter = nSpiltter; N|WR^MQD
Y]1b39O
RiAY>:
} sJ/?R:
~%:23mIk
rsvGf7C
public String getSSiteURL() !~aDmY2
{ ~C],?X(zk
return sSiteURL; 7b[vZNi_
} :~]ha
?)#}Nj<R
J\kv}v
public void setSSiteURL(String value) "(#]H;!W
{ ,n?oNU
sSiteURL = value; `BHPjp>
} DJhCe==$v
Mi"dFx^Md
xk5Z&z
public String getSFilePath() /7<l`RSr
{ KrT+Svm
return sFilePath; hGvuA9d~
} }M9L,O*^
{e8.E<f-
+3D3[.n
public void setSFilePath(String value) s4c2
{ 7w{>bYP
sFilePath = value; PYz^9Ud 6g
} h"G#} C]
:X;'37o#q
J$D#)w!$j
public String getSFileName() {wx!~K
{ Y/_b~Ahn
return sFileName; cUz7F
} MRdZ'
'Nv*ePz
J@c)SK%2h
public void setSFileName(String value) jE</a%
{ 1Lb+ &
sFileName = value; `8%2F}x}qD
} ;u0MY
$k|k5cP8x
dRXF5Ox5K}
public int getNSplitter() 1x#Z}XG
{ hqVFb.6[
return nSplitter; H`;q@
} Fh4kd>1D
-HU5E>xG
Pp[?E.]P
public void setNSplitter(int nCount) v(/T<^{cuk
{ Zi fAn
nSplitter = nCount; =FXZcP>h
} @<O Bt d
} u<l[S
Wo@0yF@
o'Byuct
/* _fu?,
**Utility.java U1t7XZ3e
*/ g9`z]qGWS:
package NetFox; 4~3 N;]X
J ;=~QYn[
W7lR54%|
public class Utility { /MB3w m
O!(M:.
ee.#Vhz
public Utility() !>{`o/dZ
{ ~4\J}Kn
|T}Q~
.>0j<|~
} {f\/2k3
0m^(|=N-
//线程睡眠 ) )q4Rh
public static void sleep(int nSecond) 8(euWS
{ c|%.B2
try{ s=&&gC1
Thread.sleep(nSecond); %EuJ~;x(Mg
} qJb9JL$s
catch(Exception e) 6.| {l8%r
{ :O}=$[
e.printStackTrace (); ]E\o<"#t/
} ao]Dm#HiO
} ua%$r[
m?]XNgT
//日志 bZ0mK$B
public static void log(String sMsg) p^~AbU'6~
{ qcSlY&6+
System.err.println(sMsg); JgJ4RmH-
} 3: 'eZcM
oz(V a!
ab5 a>w6}
public static void log(int sMsg) XjL)WgQ{i
{ dBKL_'@@}
System.err.println(sMsg); pPSmSWD?
} Lj"@JF;c
} t%$>
]uN}n;`12
r%*,pN7O
/* uz6S7I
**TestMethod.java Tji G!W8
*/ qU(,q/l
package NetFox; 3xSt -MA
|N%?7PZ(
fz[o;GTc
public class TestMethod { kQ5mIJ9(
LD]a!eY
3":vjDq$
public TestMethod() U_t[J|
{ ///xx/weblogic60b2_win.exe #1-,s.)
try{ a\60QlAk~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {Jf["Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uIOnP
SiteFileFetch fileFetch = new SiteFileFetch(bean); nKI]f`P7
fileFetch.start(); a:*8SovI
} + niz(]
catch(Exception e){e.printStackTrace ();} ]W^F!p~eC
N?Byp&rqI<
4PtRTb0<i3
} 0x&-/qce6W
jlvh'y`
ZG29q>
public static void main(String[] args) eD4D<\*
{ dux.Z9X?
new TestMethod(); N8hiv'3
} }H^h~E
} (X=JT
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