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)); "Y7 ]t:8
} /h!Y/\kI
for(int i=0;i<nEndPos.length-1;i++) \s[/{3
{ M-B-
nEndPos = nStartPos[i+1]; ).Ei:/*j
} xzRs;AXOp
nEndPos[nEndPos.length-1] = nFileLength; J:c]z9&!
} .$k2.-k
} #1v>3H(
w<uK-]t
JmR) g
//启动子线程 ;{Sgv^A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i~k9s
for(int i=0;i<nStartPos.length;i++) VS:UVe
{ N9M''H*VS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #]@<YKoV{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O;ty k_yM
nStartPos,nEndPos,i); -UPlQL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZL-YoMHc+_
fileSplitterFetch.start(); G|p3NhLgO=
} {c3u!}mW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nA\9UD<G.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W:8*Z8?7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n tfwR#j
nEndPos = " + nFileLength); .o2]ndT/J
// fileSplitterFetch[nPos.length-1].start(); nVTCbV
b$24${*'
r*'X]q|L+
//等待子线程结束 }Ot I8;>
//int count = 0; ;Ly(O'9
//是否结束while循环 $hkMJ),T~
boolean breakWhile = false; buXPeIo^VM
NdS6j'%B@7
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while(!bStop) >t/P^fr_F
{ K$H>/*&'~
write_nPos(); s{-`y`JP
Utility.sleep(500); G n_AXN
breakWhile = true; $Yr'`(Cbc
,6zH;fi
? 9.V@+i
for(int i=0;i<nStartPos.length;i++) r3@Q(Rb
{ z|Hc=AU8y
if(!fileSplitterFetch.bDownOver) .oJs"=h:m
{ ;BEg"cm
breakWhile = false; rpgr5>
break; r|XNS>V ,$
} 0,T'z,
} yn0OPjH
if(breakWhile) Ty"OJ
break; EBY=ccGE{
XIu3n9g^#
S^@I4Z
//count++; jhWNMu
//if(count>4) rx*1S/\PPc
// siteStop(); o|7]8K=
} h^P>,dy0
\8uPHf_
G\\zk
System.err.println("文件下载结束！"); 8t$a8 PE
} GfAt-huL(
catch(Exception e){e.printStackTrace ();} y)W.xR
} +e0]Y8J{
g1Q^x/
qy`95^
//获得文件长度 ExDH@Lb
public long getFileSize() }b+tD3+
{ R|T_9/#)
int nFileLength = -1; rl^_RI
try{ 29K09 0f
URL url = new URL(siteInfoBean.getSSiteURL()); [=Wn7cr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IKM=Q. 7j
httpConnection.setRequestProperty("User-Agent","NetFox"); "HW~|M7>(
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int responseCode=httpConnection.getResponseCode(); )-824?Nl:
if(responseCode>=400) k/vE|
{ $;%-<*Co
processErrorCode(responseCode); "v-\nAu
return -2; //-2 represent access is error 9YMUvd,u
} m :ROq
,UQ4`Mh^L
uXuMt a*Y
String sHeader; Hw34wQX
x`^~|Q
guv)[:cd;
for(int i=1;;i++) yzhr"5_
{ {A4"KX(U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I<*U^e
//Utility.log(in.readLine()); 8=Di+r
sHeader=httpConnection.getHeaderFieldKey(i); b1>%%#
if(sHeader!=null) lhAwTOn`Q
{ SX|b0S,
if(sHeader.equals("Content-Length")) OvU]|4h
{ CD(2A,u)/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x+(h#+F
break; w}<BO> z
} JoA^9AYhR
} i% k`/X;
else )`Tny]M
break; s4lkhoN\t
} AFL*a*
} ^r^cMksB*
catch(IOException e){e.printStackTrace ();} w-[WJ:2.
catch(Exception e){e.printStackTrace ();} #KZ- "$
nH*U
j& f-yc'i-
Utility.log(nFileLength); Ul OoMGg
7ZS5u+o
N\DEY]
return nFileLength; =35^k-VS
} wQ[~7 ,o
3*64)Ol7t]
DqrS5!C
//保存下载信息（文件指针位置） :{%6<j
private void write_nPos() {AqN@i
{ =jip* E^
try{ o87. (
output = new DataOutputStream(new FileOutputStream(tmpFile)); URmx8=q
output.writeInt(nStartPos.length); (7`&5md
for(int i=0;i<nStartPos.length;i++) #ldNWwvRGj
{ gIep6nq1`|
// output.writeLong(nPos); Bm"jf]
output.writeLong(fileSplitterFetch.nStartPos); k&ujr:)5Y5
output.writeLong(fileSplitterFetch.nEndPos); Jg3}U j2By
} /s uz>o\
output.close(); g=Q#2/UQ<
} iN5~@8jAzz
catch(IOException e){e.printStackTrace ();} 3zY"9KUN
catch(Exception e){e.printStackTrace ();} 5 |{0|mP
} {w}PV5<
^%|{>Mz;c
m!a<\0^
//读取保存的下载信息（文件指针位置） YMad]_XOP
private void read_nPos() O[3J Px
{ fXvJ3w(
try{ C78YHjy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Yn[y9;I{
int nCount = input.readInt(); bV|:MW<Wv
nStartPos = new long[nCount]; /"tVOv#
nEndPos = new long[nCount]; _sbZyL
for(int i=0;i<nStartPos.length;i++) "T?%4^:g
{ 8},!t\j#]
nStartPos = input.readLong(); /cexd_l|f
nEndPos = input.readLong(); !0`44Gbq
} Qr1%"^4
input.close(); bw9a@X
} :e ?qm7cB
catch(IOException e){e.printStackTrace ();} [zn`vT
catch(Exception e){e.printStackTrace ();} ,'m<um
} -lRXH7|X
Sb>;k(;`:
"]JE]n}Ulg
private void processErrorCode(int nErrorCode) fOm=#:O
{ BM&95p
System.err.println("Error Code : " + nErrorCode); j!iimdq
} Uc!}D
"X's>uM
POfvs]
//停止文件下载 Ui@Q&%b
public void siteStop() ,xuqQ;JX
{ <<6i6b
bStop = true; 3%|LMX]M5_
for(int i=0;i<nStartPos.length;i++) U PGS
fileSplitterFetch.splitterStop(); ~A}"s-Kq5
WM*[+8h
0SwWLq
} o>311(:
} NcZ6!wWdE
//负责部分文件的抓取 `]#DdJ_|
**FileSplitterFetch.java )/HSt%>
*/ lV]hjt-L 2
package NetFox; L10Vq}W"
z^gf@r
ha1 J^e
import java.io.*; 1mwb&j24n3
import java.net.*; pi q%b]
aU<0<Dx
xv]P-q0
public class FileSplitterFetch extends Thread { m%m/#\J E
"uDLty?*k
7C9qkQ Jqn
String sURL; //File URL ]t\fw'
long nStartPos; //File Snippet Start Position i{I'+%~R
long nEndPos; //File Snippet End Position 1>c`c]s3
int nThreadID; //Thread's ID 6{8qATLR
boolean bDownOver = false; //Downing is over fa8vY
boolean bStop = false; //Stop identical ZtlF]k:MV
FileAccessI fileAccessI = null; //File Access interface B%6>2S=E
Os?G_ziIB
Jt43+]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T|GRkxd,E3
{ &dp(CH<De
this.sURL = sURL; <8|vj2d2
this.nStartPos = nStart; -A(]",*J
this.nEndPos = nEnd; Fx~=mYU
nThreadID = id; ^6Q(he
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I;qeDCM
} @2v L'6
)a.w4dH
j/TsHJ=
public void run() 36,qh.LKn
{ FTI[YR8?Y
while(nStartPos < nEndPos && !bStop) Xt(w+
{ Bcg\p}
0t*JP
bmr.EB/
try{ \om$%FUP
URL url = new URL(sURL); *LOpbf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vRp =L54z
httpConnection.setRequestProperty("User-Agent","NetFox"); !lG5BOJM
String sProperty = "bytes="+nStartPos+"-"; ;JDn1(6
httpConnection.setRequestProperty("RANGE",sProperty); ZMids"Xdf
Utility.log(sProperty); ?;i O
\CM/KrCR
rBye%rQRq
InputStream input = httpConnection.getInputStream(); 'b]GcAL
//logResponseHead(httpConnection); PEW^Vl-6q
3kx/Q#
%k_R;/fjW
byte[] b = new byte[1024]; 6AKH0t|4
int nRead; N&K:Jp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P6&@fwJ<
{ 9eo$Duws
nStartPos += fileAccessI.write(b,0,nRead); Bf~
//if(nThreadID == 1) v3x_8n$C9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "X4OUk
} \\AufAkJ
/)ps_gM
~cbq5||
Utility.log("Thread " + nThreadID + " is over!"); r&@#,g
bDownOver = true; !FX0Nx=oi
//nPos = fileAccessI.write (b,0,nRead); }`E5I&r4
} r"d/9
catch(Exception e){e.printStackTrace ();} vz#VW
} 2>Hl=bX
} ~McmlJzJG
-^]8wQU
4G"T{A`O
//打印回应的头信息 Y*/:IYr`
public void logResponseHead(HttpURLConnection con) >&6pBtC_
{ lM`M70~
for(int i=1;;i++) HhDiGzOSi
{ [g`9C!P-G
String header=con.getHeaderFieldKey(i); ~B;kFdcVXn
if(header!=null) ()e.J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NNLZ38BV7
Utility.log(header+" : "+con.getHeaderField(header)); hNgbHzW
else 3/>T/To&2
break; 3}e-qFlV8,
} (JHzwI8+
} {G&*\5W
~XQj0'
z )s{>^D
public void splitterStop() =Ryh@X&
{ 0h/gqlTK1
bStop = true; 649{\;*4
} O32p8AxEz
7ZarXv z
RAYDl=}
} Ss6mN;&D
)'3(=F$+l
*@/1]W
/* > 2_xRn<P
**FileAccess.java nt.A X
*//文件访问(定位，写) gEcRJ1Q;C
package NetFox; 0NrUB
import java.io.*; x>:~=#Vi
kx&Xk0F_g
95LZG1]Rb
public class FileAccessI implements Serializable{ .|W0B+Z8
qn) VKx=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Br^4N9
RandomAccessFile oSavedFile; h&@A'om~
long nPos; hG51jVYtw
WO$9Svh8
lZ]x #v
public FileAccessI() throws IOException ~Sy/q]4ys*
{ C".nB12
this("",0); 7i^7sT8t
} +g/TDwyVH
K;kaWV
)y>o;^5'
public FileAccessI(String sName,long nPos) throws IOException A+Uil\%
{ 7^1yZ1(
oSavedFile = new RandomAccessFile(sName,"rw"); GF4k
this.nPos = nPos; jZwv!-:
oSavedFile.seek(nPos); r:pS[f|4\
} BkywYCWZ )
v:/+OzY
<ua`WRQr
public synchronized int write(byte[] b,int nStart,int nLen) 7> ~70
{ C>l{_J)n
int n = -1; w_zUA'n+
try{ v C,53g
oSavedFile.write(b,nStart,nLen); {Yq"%n'0
n = nLen; D1w;cV7/d
} t!}QG"ma
catch(IOException e) `y"(\1
{ \l)Jb*t
e.printStackTrace (); <X>lA
} Tx+!D'>
^G:}%4
tYb8a
return n; M"XILNV-~
} Ek'~i
vbFi#|EU
YY{0WWua
} w5/`_m!
^(}D
O5rHN;\_
/* d_t>
**SiteInfoBean.java f3r\X
*/ RLy2d'DS
package NetFox; U&F1}P$fb
!4;A"B(
#kGgzO
public class SiteInfoBean { 18`YY\u(
WG~|sLg
MTnW5W-r9
private String sSiteURL; //Site's URL kHWW\?O
private String sFilePath; //Saved File's Path oe (})M
private String sFileName; //Saved File's Name +/"Ws'5E
private int nSplitter; //Count of Splited Downloading File @*Y"[\"$
mGZJ$|
[N@t/^gRC
public SiteInfoBean() 11"- taWj
{//nSplitter的缺省值为5 4lM)ZDg
//default value of nSplitter is 5 ^|^ywgK
this("","","",5); 5OJ8o>BF
} Bqcih$`BVU
;`")3~M3*
z (1zth
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g3V bP
{ `EBI$;!
sSiteURL= sURL; VL =19[
sFilePath = sPath; J\@ r~x5G
sFileName = sName; YLXLaC[
this.nSplitter = nSpiltter; c[IT?6J4
kT-dQ32
o"kVA;5<G
} 0 _n Pq
W?>C$_p C
)a7nr<)aU
public String getSSiteURL() KF.O>c87&
{ @~=*W5
return sSiteURL; Vx Vpl@
} }]<Ghns
]2_b_ok
^ gMkQYo(#
public void setSSiteURL(String value) (yJY/|
{ =%)Y, )"
sSiteURL = value; u# TNW.
} VxP cC+
Tqf:G4!
=K\xE"
public String getSFilePath() **G5fS.^W
{ gh?3[q6
return sFilePath; /!i`K{
} 4\_~B{kzZ
BNw};.lO
hEh` cBO
public void setSFilePath(String value) uGc0Lv4i/
{ IDY2X+C#U
sFilePath = value; `;}w!U
} "*bP @W
mXPA1#qo
mx!EuF$I
public String getSFileName() p9y@5z
{ X T<SR]
return sFileName; 5%jy7)8C
} ^$AJV%3wI
KSYHG
_2a)b(<tF
public void setSFileName(String value) hh[@q*C
{ )Tl]1^
sFileName = value; 1xD?cA\vu
} R*`=Bk0+
1KadT7<0}
xG1(vn83gq
public int getNSplitter() S8,e`F
{ ,Dy9-o
return nSplitter; ,@]*Xgt=
} _B?Hw[cc
0aqq*e'c
;U&~tpd
public void setNSplitter(int nCount) E*vh<C
{ .O&[9`"'
nSplitter = nCount; DP.Y<V)B
} 2w;Cw~<=d
} ~='}(Fg:
W) ?s''WE;
%%T?LRv
/* +&4@HHU{G
**Utility.java (5l'?7
*/ jfU$qo!gi
package NetFox; w&>*4=^a
.^wBv 'Y
_/NPXDL
public class Utility { tRbZX{
F*JbTEOn
tI<6TE'!p#
public Utility() L>n^Q:M
{ T[- %b9h>
pD]2.O
XG!^[ZDs
} zgl$ n
]zz%gZz
//线程睡眠 KP_7h/e
public static void sleep(int nSecond) &],O\TAul
{ ~g}blv0q+B
try{ eB9F35[
Thread.sleep(nSecond); +bk+0k9k5
} i(4.7{*
catch(Exception e) QN;GMX5&
{ ]l}bk]
e.printStackTrace (); 5`QfysR5
} epI~w
} y*E{X
LhSXz>AX
//日志 Mehp]5*
public static void log(String sMsg) USJ4Z
{ ]/|DCxQ
System.err.println(sMsg); s$~H{za
} 1 J[z ![Tf
TA+#{q+a
_TyQC1 d
public static void log(int sMsg) OI:T#uk5
{ 9hgIQl
System.err.println(sMsg); C't%e
} !Pu7%nV.
} jX,A.
M"foP@
ceLr;}?Ws
/* knzQ)iv&&
**TestMethod.java [OFT!=.y &
*/ O]l-4X#8F
package NetFox; z=4E#y`?U
@"iNjqxh
+!t *LSF
public class TestMethod { Xy9'JVV6
iig&O(,
OA7=kH@3c
public TestMethod() UJ`%uLR~
{ ///xx/weblogic60b2_win.exe @^`5;JiUk
try{ G }M!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V3_qqz}`r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hP/uS%X
SiteFileFetch fileFetch = new SiteFileFetch(bean); nZ`=Up p)
fileFetch.start(); {h;i x
} 4-\4G"4
catch(Exception e){e.printStackTrace ();} Koz0Xy
k,y#|bf,Y
th=45y"C
} ?hW(5]p|
/sl#M
B,Jn.YX
public static void main(String[] args) 'IER9%V$
{ _K~?{".
new TestMethod(); 'v@1_HHW\
} K=2j}IPe
} vw` '9~
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