http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); BiHBu8<
} #tBbvs+%
for(int i=0;i<nEndPos.length-1;i++) rq6(^I
{ A\.M/)Qo
nEndPos = nStartPos[i+1]; *4[3?~_B#6
} Rm *"SG
nEndPos[nEndPos.length-1] = nFileLength; 4Kt?; y ;
} 37!}8
} eA_1?j]E3
_&JlE$ua7
Fu m1w
//启动子线程 W?/7PVGv5h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8F4#E U
for(int i=0;i<nStartPos.length;i++) H,=??wN
{ 2&!G@5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4k$BqM1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -acW[$t
nStartPos,nEndPos,i); 'L0 2lM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "Rs^0iT7>
fileSplitterFetch.start(); XUUS N
} 5'>(|7~%\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @eT!v{o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g >-iBxml
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", it>FG9hVo
nEndPos = " + nFileLength); o*I-~k
// fileSplitterFetch[nPos.length-1].start(); A"z')
NY1olnI
4"wuqr|o
//等待子线程结束 R4QXX7h!
//int count = 0; {n%F^ky+7
//是否结束while循环 Q} f=Ye(&}
boolean breakWhile = false; d%4!d_I<
<(@m913|
aCFO]
while(!bStop) Sjj&n S
{ 1"~@UcJ
write_nPos(); "o}3i!2Qr
Utility.sleep(500); LfrS:g
breakWhile = true; $N5}N\C:a
i6(y Bn
oe4Fy}Y_;
for(int i=0;i<nStartPos.length;i++) eSywWSdf0
{ !>;p^^e
if(!fileSplitterFetch.bDownOver) }r*t V)
{ qV^,muyoG
breakWhile = false; ShHm7+fV
break; ],&WA?>G
} d^WVWk K
} <q%buyQna
if(breakWhile) >K;p+( <6
break; g5X+iV
+@AN+!(
}N*6xr*X+
//count++; ;&^S-+
//if(count>4) Qy5\qW'
// siteStop(); x:"_B
} 8GV$L~i
TpuN[Y
7oh6G
System.err.println("文件下载结束！"); N6EH
} P0DvZV8
catch(Exception e){e.printStackTrace ();} 4U~[8U}g
} ]f-< s,@
'X"@C;q
C8DZ:3E$c
//获得文件长度 P[?~KNS:/
public long getFileSize() u==bLl=$
{ mz3!HksZ"
int nFileLength = -1; ul>$vUbyf
try{ 6*/0 yGij
URL url = new URL(siteInfoBean.getSSiteURL()); 5L"{J5R}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); | ?~-k[|
httpConnection.setRequestProperty("User-Agent","NetFox"); x'+lNlv
TfDx> F$
'|G_C%,B
int responseCode=httpConnection.getResponseCode(); }>6=(!
if(responseCode>=400) J}hi)k
{ _hMMm6a|
processErrorCode(responseCode); @]Aul9.h
return -2; //-2 represent access is error *Ny^XQ_X
} ^EN_C<V;"d
N9r02c
kb Fr
String sHeader; W r);A{
h$_Wh(
l&dHH_m3
for(int i=1;;i++) Xl.h&x0? 8
{ 68kxw1xY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KCGs*kp>
//Utility.log(in.readLine()); z%Op_Ddp
sHeader=httpConnection.getHeaderFieldKey(i); {W62%>v
if(sHeader!=null) C=t:0.:PJ
{ @ZK#Y){
if(sHeader.equals("Content-Length")) cmmH)6c>
{ xO`w|k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `Yn^ -W
break; 1c(1YGuH
} U#gHc:$
} A=o p R
else 2[}^ zTtA
break; R0(Nw7!d/[
} U SXz
} {d.`0v9h
catch(IOException e){e.printStackTrace ();} /tikLJ
catch(Exception e){e.printStackTrace ();} 3Wrl_V
YQG[8I
JUok@6
Utility.log(nFileLength); !u.{<51b
,--/oP
!bFa\6]q
return nFileLength; :c"J$wT/
} pv+FPB
T {a%:=`
NIrK+uC.d
//保存下载信息（文件指针位置） UB@>i3
private void write_nPos() [-f0s;F1%
{ Z'6 o$Xv
try{ Sdz!J 1
output = new DataOutputStream(new FileOutputStream(tmpFile)); [-bL>8
output.writeInt(nStartPos.length); 12])``9
for(int i=0;i<nStartPos.length;i++) Ih!UL:Ckh
{ yHLclv
// output.writeLong(nPos); <1.].A@b*
output.writeLong(fileSplitterFetch.nStartPos); H6 ( ~6Bp5
output.writeLong(fileSplitterFetch.nEndPos); 0PE $n
} EJO:3aKa
output.close(); =<s+cM
} \K9XG/XIx
catch(IOException e){e.printStackTrace ();} p+@Wh3
catch(Exception e){e.printStackTrace ();} )fP,F(
} J\b,rOIf
Jg/l<4,K,
zNuiBLxDs
//读取保存的下载信息（文件指针位置） UTc$zc7
private void read_nPos() T9jp*
{ M.zS +
try{ 8Y3c,p/gS>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [4]lAxrRF
int nCount = input.readInt(); x~!B.4gT2
nStartPos = new long[nCount]; g2^7PtJg
nEndPos = new long[nCount]; *E+2E^B
for(int i=0;i<nStartPos.length;i++) X?z5IL;rt
{ Yr-a8aSTE5
nStartPos = input.readLong(); 9~I\WjB "
nEndPos = input.readLong(); N{46DS
} RQWVjF#
input.close(); YR'?fr
} n9]^v-]K
catch(IOException e){e.printStackTrace ();} H"WkZX
catch(Exception e){e.printStackTrace ();} k:4 Zc3
} f)H6 nl7r
~0w7E0DE[
yGT"k,a
private void processErrorCode(int nErrorCode) oF,XSd
{ ^_9 ^iL
System.err.println("Error Code : " + nErrorCode); yc|C}oQF
} ^W9[PE#F
QG?7L_I
e &^BPzg
//停止文件下载 xr&wV0O'
public void siteStop() \NhCu$'
{ bYQ h{q
bStop = true; @^a6^*X>
for(int i=0;i<nStartPos.length;i++) R?qVFMQ
fileSplitterFetch.splitterStop(); il<D e]G
F')T:;,s
z}.!q{Q
} MVg`6&oH
} t>7t4>X
//负责部分文件的抓取 gGw6c" FRQ
**FileSplitterFetch.java -}%'I]R=
*/ Q-F'-@`(C
package NetFox; #i-!:6sLA
OHssUt
N?Mmv|
import java.io.*; Jc~^32
import java.net.*; (9';zw
uEWWY t
ioi0^aM
public class FileSplitterFetch extends Thread { %=/Y~ml?
0(Y$xg
fpM4q
String sURL; //File URL -kZz,pNQ,
long nStartPos; //File Snippet Start Position >4ebvM 0|
long nEndPos; //File Snippet End Position XtT;UBE
int nThreadID; //Thread's ID L'6_~I
boolean bDownOver = false; //Downing is over }!0,(<EsV
boolean bStop = false; //Stop identical eM/|"^%
FileAccessI fileAccessI = null; //File Access interface H|0B*i@81
Y((z9-`
lk \|EG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LoOyqJ,
{ \9Itu(<f
this.sURL = sURL; 5U|f"3&8
this.nStartPos = nStart; + h`:qB
this.nEndPos = nEnd; lcJ`OLG
nThreadID = id; .}ohnnJB0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p!' "hx
} on*?O O'
AbZ:AJ(
fL83:<RK
public void run() bsM`C]h&
{ #Q 2$v;
while(nStartPos < nEndPos && !bStop) uWx/V+w
{ 1kio.9NIp
?P<&8eY
s?~Abj_
try{ ?-#w [J'6
URL url = new URL(sURL); i.cSD%*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jA=uK6m
httpConnection.setRequestProperty("User-Agent","NetFox"); UbC)XiO
String sProperty = "bytes="+nStartPos+"-"; W}Nd3
httpConnection.setRequestProperty("RANGE",sProperty); 1uB}Oe2~
Utility.log(sProperty); *X%`MN
'9auQ(2
~Ufcy{x#
InputStream input = httpConnection.getInputStream(); Yr-,0${m
//logResponseHead(httpConnection); 'AeU
WRVKh
kG?tgO?*
byte[] b = new byte[1024]; g/`i:=
int nRead; *sAoYx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xd(AUl4qY
{ xg'0YZ\t
nStartPos += fileAccessI.write(b,0,nRead); ,"h$!k"$g
//if(nThreadID == 1) RF6(n8["MW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (d#?\
} 0R_ZP12
y::KjB 0
>/e#Z h
Utility.log("Thread " + nThreadID + " is over!"); O(&EnNm[2
bDownOver = true; G9E?
//nPos = fileAccessI.write (b,0,nRead); eDaVoc3
} O;H/15j:sK
catch(Exception e){e.printStackTrace ();} .]r[0U
} M?}2
} }[AIE[
EVb'x Zr
>#!n"i;
//打印回应的头信息 OE4 2{?)
public void logResponseHead(HttpURLConnection con) JG/sKOlA
{ ?[XH`c,
for(int i=1;;i++) ]t(g7lc}U
{ (6 0,0|s
String header=con.getHeaderFieldKey(i); =@3Qsd
if(header!=null) T+sO(;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jS R:ltd
Utility.log(header+" : "+con.getHeaderField(header)); O~qB
else ^gb2=gWZ<
break; CZ]+B8Pl(x
} :FxZdE
} 4jG@ #
kx'6FkZPIr
>St
public void splitterStop() 6 _73
{ vKaX,)P;?
bStop = true; {Ziq~{W_
} NiWooFPKJ
&mY<e4
]&}?J:+?0E
} P_b00",S
!_x-aro3<
P6IhpB59
/* + FLzK(
**FileAccess.java Q@d X2
*//文件访问(定位，写) C}+(L3Z
package NetFox; t$Qav>D
import java.io.*; Q%t8cJL
"h:xdaIE/p
Nk^#Sa?
public class FileAccessI implements Serializable{ y#x]?%m
N:&^ql4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !sR`]0
RandomAccessFile oSavedFile; {0Leua
long nPos; A>d*<#x
C/]0jAAE7
B&.XGo)
public FileAccessI() throws IOException a<vCAFQ
{ Gc SX5c
this("",0); (a)d7y.oo
} CZbp}:|
'9^x"U9c
~~yo& ]
public FileAccessI(String sName,long nPos) throws IOException E-!`6
{ MNJ$/l)h
oSavedFile = new RandomAccessFile(sName,"rw"); s6KZV@1
this.nPos = nPos; u1>|2D
oSavedFile.seek(nPos); \W*ouH
} *4r;H2%c
%X#Wc:b
L4Kkbt<x
public synchronized int write(byte[] b,int nStart,int nLen) m3,]j\
{ DmD*,[rD
int n = -1; wAy;ZNu
try{ 3YRhqp"E
oSavedFile.write(b,nStart,nLen); #M8"b]oh6
n = nLen; )8e_<^M
} <L5[#V_
catch(IOException e) Zx`hutCv
{ n]_8!NU
e.printStackTrace (); |yQ3H)qB#
} "3}Bv X
xJZbax[
yQCfn1a)
return n; L! Q&?xP
} Q=w\)qJ
Y+WOU._46I
sFB; /*C
} j;<;?IW
Oja)J-QXb
RQ|!?\a=
/* )2FS9h.t
**SiteInfoBean.java [l'~>
*/ \Fc"Q@.u
package NetFox; )zen"](cze
5H?`a7q N
xB 4A"|
public class SiteInfoBean { O2A Z|[*I
:2
b~v
private String sSiteURL; //Site's URL .F}ZP0THnZ
private String sFilePath; //Saved File's Path }U+gJkY2
private String sFileName; //Saved File's Name W^al`lg+y
private int nSplitter; //Count of Splited Downloading File aoMQ_@0
o-7>^wV%BD
(~/D*<A
public SiteInfoBean() }%_x T
{//nSplitter的缺省值为5 Z/56JYt!~
//default value of nSplitter is 5 &*L:4By)]
this("","","",5); ugucq},[
} [#uX{!q'
=s1"<hH}O)
\asF~P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0>Ecm#
{ U*v//@WbH
sSiteURL= sURL; WynHcxC
sFilePath = sPath; c?b?x 6 2
sFileName = sName; `h :&H,N
this.nSplitter = nSpiltter; I=Ws /+
U}7$:hO"dX
Cl4y9|
} QQ1+uY
<k}>eGn
LK/gG6n5M0
public String getSSiteURL() <k/'mBDk
{ (/Z~0hA[Q
return sSiteURL; "t`r_Aw
} 18V*Cu
H>-,1/IY
w0tlF:Eg
public void setSSiteURL(String value) S #&HB
{ BeaX 0#\
sSiteURL = value; Lm:O vVVB
} NZ9`8&93
,LWM}L
Af ^6
public String getSFilePath() RYS]b[-xZz
{ kH1l -mxz
return sFilePath; HSp*lHU
} _N9yC\
(al7/EhY
DV*8Mkzg
public void setSFilePath(String value) !0*=z~
{ }+i ZY\t
sFilePath = value; m!N_TOl-^
} A{mbL2AxwC
1S0Hc5vw
"p2 $R*ie
public String getSFileName() qPH]DabpI
{ `S{< $:D
return sFileName; :[|`&_D9J
} ;oWhTj`
^X"G~#v=q
;QREwT~H
public void setSFileName(String value) C<6u}czA
{ &Mo=V4i>
sFileName = value; TBrAYEk
} NVeb,Pf
`H+ 7Hj
/=,^fCCN
public int getNSplitter() i "62+
{ `Ft`8=(
return nSplitter; DtXXfp@;
} ]A9Vh
~W%A8`9
+=$]fjE?
public void setNSplitter(int nCount) W4|1wd}.t
{ V\!FD5%
nSplitter = nCount; DY~~pi~
} *z` {$hc
} V1xpJ
x #BUIi
3vQ?vS|2
/* F@"Xd9q?
**Utility.java C&zgt :q6}
*/ *G'zES0x
package NetFox; k[A=:H1"
j05ahquI
[WY NA-O
public class Utility { JjyQ
jEit^5^5|
oel3H5Nz
public Utility() i3rvDch
{ w+2:eFi=/
D@>P%k$$s>
T>kJB.V:oQ
} T7Lk4cU
V6BCW;
//线程睡眠 s/`4]B;2U
public static void sleep(int nSecond) YAC=V?U-#
{ =WJ*$j(
try{ EOVHTDkKf
Thread.sleep(nSecond); Fm*n>^P@Y
} J@(*(oQb
catch(Exception e) pOlQOdl
{ wvx N6
e.printStackTrace (); 75Jh(hd(
} XHlPjw
} ]*sXISg1
YpL{c*M
//日志 '`/1?,=
public static void log(String sMsg) ((SN We
{ &y;('w
System.err.println(sMsg); )|~pocXt<
} t,]r%
Plpt7Pa_
?[{_*qh
public static void log(int sMsg) Qv=F'
{ g*]Gc%
System.err.println(sMsg); $KDH"J
} MD`1KC_m
} Bs7/<$9K/
eaSf[!24"
)w\E^
/* ape\zZCV
**TestMethod.java `>.^/SGu>?
*/ ly!vbpE_
package NetFox; %3"xn!'vf
g>L4N.ZH_v
25:[VH$:4
public class TestMethod { aicvu(%EE
]6:|-x:m
](^$5Am
public TestMethod() nU^-D1s{
{ ///xx/weblogic60b2_win.exe REEs}88);'
try{ &?(<6v7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z4&,KrV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8[PD`*w
SiteFileFetch fileFetch = new SiteFileFetch(bean); r)4GH%+?fv
fileFetch.start(); 6"OwrJB
} eUY/H1
catch(Exception e){e.printStackTrace ();} fu=GgD*
IjshxNk
zCpsGr
} 2rzOh},RS
=sp5.-r
Lo<-;;vQ
public static void main(String[] args) JY5)^<.d
{ >EacXPt-O
new TestMethod(); ZqONK^
} <6!;mb ;cX
} Q+i
点击下载更多相关资料