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)); D0a3%LBS/2
} k&SI-jxj
for(int i=0;i<nEndPos.length-1;i++) ^h\Y.
{ 6=i@ttAK
nEndPos = nStartPos[i+1]; 23~KzC
} \S`|7JYW
nEndPos[nEndPos.length-1] = nFileLength; 8S*W+l19f
} %:hU:+G E
} v\b@;H`
w@"l0gm+u[
0z:BSdno
//启动子线程 mnS F=l;;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sDzlNMr?P+
for(int i=0;i<nStartPos.length;i++) BP`'1Ns
{ Fy-N U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PcK;L(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4J6,_8`U
nStartPos,nEndPos,i); Y;OqdO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B$@fE}
fileSplitterFetch.start(); 2P4$^G[
} ;E]^7T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GtSvb6UNn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >xJh!w<pB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w,v~
nEndPos = " + nFileLength); 9$oU6#U,h
// fileSplitterFetch[nPos.length-1].start(); 1feS/l$
I-?Dil3
Jt}0%C3d
//等待子线程结束 >@wyiBU
//int count = 0; ?RVY%s;g
//是否结束while循环 _k2*2db
boolean breakWhile = false; nFY6K%[
VQ((c:+!
oD>j26Q
while(!bStop) VLO!hA#
{ +9d]([Lx
write_nPos(); Y] "_}
Utility.sleep(500); ZAcH`r*
breakWhile = true; #Kd^t=k
)`B n"=
[>N`)]fP
for(int i=0;i<nStartPos.length;i++) "o.g}Pv
{ p{BBqKv
if(!fileSplitterFetch.bDownOver) FqT2+VO~
{ 2N$yn
breakWhile = false; Zn]njf1x
break; fF*{\
} 6I`Lszs
} EA+}Rf6}
if(breakWhile) slWO\AYiO
break; ~KF>Jow?Y
BQTibd
;Q&|-`NK
//count++; Y4.t:Uzr
//if(count>4) ~xSAR;8
// siteStop(); ollk {N
} sq~9 l|F
A:-r2;xB
Ug1n4X3FKn
System.err.println("文件下载结束！"); lE@ V>%b
} d}`Z| ex
catch(Exception e){e.printStackTrace ();} 8Q2qroT
} ':jsCeSB
p^uX{!
R<GnPN:c
//获得文件长度 G$)f5_]7{
public long getFileSize() >PBP:s1f4>
{ eVy>
int nFileLength = -1; $x'p+&n\
try{ [hl8LP+~
URL url = new URL(siteInfoBean.getSSiteURL()); -lNq.pp3-$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tB i16=
httpConnection.setRequestProperty("User-Agent","NetFox"); R&`; C<6}D
7eyVm;LQD
6~@S,i1
int responseCode=httpConnection.getResponseCode(); fi.[a8w:W
if(responseCode>=400) QSxR@hC
{ 3w-0IP]<
processErrorCode(responseCode); $V0G[!4
return -2; //-2 represent access is error Bl"BmUn
} >.)m|,
:g`j gn0
][IEzeI_LN
String sHeader; )* \N[zm
d}2$J1`
wG\ +C'&~
for(int i=1;;i++) Wu!s
{ WE|-zo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'zg; *)x1/
//Utility.log(in.readLine()); wcI?.
sHeader=httpConnection.getHeaderFieldKey(i); S);SfNh%CL
if(sHeader!=null) )*wM DM5q
{ E1&9( L5
if(sHeader.equals("Content-Length")) 4%s6 d,6"
{ p]-\\o}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7|/Ct;oO:
break; $yA>j (k4
} x&kM /z?/
} ~5Cid)Q}@o
else &Is}<Ew
break; jrKRXS
} UbnX%2TW
} Hido[
catch(IOException e){e.printStackTrace ();} &# ?2zbZ
catch(Exception e){e.printStackTrace ();} v,VCbmc
$xK2M
2`?58&
Utility.log(nFileLength); ip`oL_c
Q2L>P<87T
EL?6x
return nFileLength; qZS]eQW.
} &O:IRR7p
Yi5^#G
,L.*95,
//保存下载信息（文件指针位置） @> ]O6P2
private void write_nPos() ;;zQVD )X
{ nbMxQODk
try{ ; m]KKB
output = new DataOutputStream(new FileOutputStream(tmpFile)); hN5?u:
output.writeInt(nStartPos.length); m 3Y@p$i5
for(int i=0;i<nStartPos.length;i++) fQkfU;5
{ t6+c"=P#
// output.writeLong(nPos); ]"2;x
output.writeLong(fileSplitterFetch.nStartPos); C2[* $ 1U
output.writeLong(fileSplitterFetch.nEndPos); XDtMFig
} 1[g -f,
output.close(); uSl&d
} u3B[1Ae:K
catch(IOException e){e.printStackTrace ();} YXi'^GU@
catch(Exception e){e.printStackTrace ();} UBm L:Qv
} o^!_S5zKe.
!'jZ !NFO
Jx jP'8
//读取保存的下载信息（文件指针位置） +~x'1*A_
private void read_nPos() %lbDcEsf9
{ Oe/&Ryj=mm
try{ g"dq;H
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <*/IV<
int nCount = input.readInt(); %wDE+&M
nStartPos = new long[nCount]; >STAPrBp+
nEndPos = new long[nCount]; 5uidi
for(int i=0;i<nStartPos.length;i++) JoCZ{MhM
{ KmYSYNr@,
nStartPos = input.readLong(); sYG:\>}ie
nEndPos = input.readLong(); )9]DJ!]&Q"
} .S{FEV
input.close(); l 10p'9n
} g5OKhL0u
catch(IOException e){e.printStackTrace ();} x%!Ea{s
catch(Exception e){e.printStackTrace ();} 2&,jO+BqE@
} tpY]Mz[J
nc2=S^Fqu
9*&c2jh
private void processErrorCode(int nErrorCode) /TndB7l"3
{ UD!-.I]
System.err.println("Error Code : " + nErrorCode); t4P`#,:8
} e2><Y<
GGQ%/i]:
%6%~`((4
//停止文件下载 ~Oc:b>~
public void siteStop() b4R;#rm
{ 3i;sB
bStop = true; y v58~w*"
for(int i=0;i<nStartPos.length;i++) mM$|cge"
fileSplitterFetch.splitterStop(); JH|]B|3
@7? O#WmL
Xt.ca,`U
} _ g8CvH)?!
} E-`3}"{
//负责部分文件的抓取 ++=f7yu
**FileSplitterFetch.java vmj'X>Q
*/ ;}dvc7
package NetFox; #aua6V!"
QhJuH_f 0
B4Fuvi
import java.io.*; $A;%p6PO)
import java.net.*; m4r<=o
cSD$I^$oq
euyd(y$'k
public class FileSplitterFetch extends Thread { # E{2 !Z
yp!7^
A/c#2
String sURL; //File URL )Ggv_mc h
long nStartPos; //File Snippet Start Position RD|DHio%
long nEndPos; //File Snippet End Position {44#<A<
int nThreadID; //Thread's ID `9* |Y8:
boolean bDownOver = false; //Downing is over ) w1`<7L
boolean bStop = false; //Stop identical DP8%/CV!*
FileAccessI fileAccessI = null; //File Access interface lS96Z3k"SB
Due@'
WqJrDj~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jl"su:y
{ ! }>CEE
this.sURL = sURL; I !J'
this.nStartPos = nStart; jf^BEz5
this.nEndPos = nEnd; ,gdud[&|;
nThreadID = id; rQD^O4j R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OfK>-8
} t}YT+S
&e6!/y&
^?8/9o
public void run() vk4Q2P
{ /U 3Uuk:
while(nStartPos < nEndPos && !bStop) /& W&
{ $3=S\jyfK
ZYS]Et[Q
`*ALb|4ilG
try{ bgYUsc*uR
URL url = new URL(sURL); H:F'5Zt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %6W%-`
httpConnection.setRequestProperty("User-Agent","NetFox"); {[)n<.n[g
String sProperty = "bytes="+nStartPos+"-"; 8Drz i!}
httpConnection.setRequestProperty("RANGE",sProperty); +P=IkbxAO
Utility.log(sProperty); )`BKEaf
p/U{*i]t
4:9N]1JCb
InputStream input = httpConnection.getInputStream(); mIZ6[ ?
//logResponseHead(httpConnection); :2.<JUDM
0T7t.
Rc vp@
byte[] b = new byte[1024]; ij,Rq`}l
int nRead; #,9s\T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \c}pzBFd
{ aH?+^f"D
nStartPos += fileAccessI.write(b,0,nRead); >r3SF3XMq
//if(nThreadID == 1) b]gVZ-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RcC5_@W
} \^1S:z
ox*>HkV
Ae[fW97
Utility.log("Thread " + nThreadID + " is over!"); SLW|)Q24
bDownOver = true; {2)).g
//nPos = fileAccessI.write (b,0,nRead); h343$,))u
} 2FcNzAaV
catch(Exception e){e.printStackTrace ();} brX[-
} 5ZX
} +BVY9U?\"
E/zclD5S
:,ucJ|
//打印回应的头信息 #g/m^8n?s
public void logResponseHead(HttpURLConnection con) \10KIAQ
{ Z(XohWe2
for(int i=1;;i++) 3 "iBcsLn
{ "AP$)xM-:
String header=con.getHeaderFieldKey(i); )Dp0swJ
if(header!=null) B@U'7`v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); edo+ o{^
Utility.log(header+" : "+con.getHeaderField(header)); nMK$&h,{
else k1.%ZZMM
break; c'>_JlG~
} x"n++j
} & 'CUc/,
npd:aGx
15S&,$1&
public void splitterStop() {;N2 &S o
{ uM\5GK
bStop = true; -xG6J.S
} Bi2 c5[3
shR|
UwxszEHC
} }<YU4EW
U\u07^h[
dVUe!S`
/* W4,'?o
**FileAccess.java ('{aOiSH
*//文件访问(定位，写) ~yt7L,OQ
package NetFox; `^] D;RfE
import java.io.*; @C<ofg3E
&)jq3
tY>Zy1hlI
public class FileAccessI implements Serializable{ Y]7503J
,kf.'N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^|SiqE
RandomAccessFile oSavedFile; 2]<.m]
long nPos; j XH9Pq4
3FtL<7B'.
\_
public FileAccessI() throws IOException 3vKTCHbk9
{ J?dLI_{<
this("",0); !Sw=ns7
} OIJT~Z}
v$D U q+
x5CMP%}d
public FileAccessI(String sName,long nPos) throws IOException BN `2UVH
{ :G6aO
oSavedFile = new RandomAccessFile(sName,"rw"); r^a:s]
this.nPos = nPos; T-#4hY`
oSavedFile.seek(nPos); ="5D}%
} J&s$Wqf
^vPsp?
d]Y;rqjue
public synchronized int write(byte[] b,int nStart,int nLen) MI'"Xzp{s
{ 4=ovm[
int n = -1; ,zdGY]$
try{ j!w{
oSavedFile.write(b,nStart,nLen); =@0J:"c
n = nLen; Aj|->Y
} |g.CS$'#Nt
catch(IOException e) 33EF/k3vW
{ Av?R6
e.printStackTrace (); <zL_6Y2
} eZ+6U`^t
.>eRX%
NhCucSU<K
return n; P1Z"}Qw
} /OWwC%tM/
xnt)1Q
;Y[D#Ja-
} n|{#5#
SDC'S]{ew
N[e,%heR
/* 5 ty2e`~K
**SiteInfoBean.java /IG{j}
*/ ROmmak(y8
package NetFox; 1C8xJ6F
n."n?C'{
v\5O\ I ^
public class SiteInfoBean { W} i6{Vh
F_(~b
s*[ I"iE
private String sSiteURL; //Site's URL .whi0~i
private String sFilePath; //Saved File's Path uE41"?GS
private String sFileName; //Saved File's Name cZQ8[I
private int nSplitter; //Count of Splited Downloading File W~0rSVD$<z
g{Al:}u>
H7GI`3o
public SiteInfoBean() ZX` \so,&,
{//nSplitter的缺省值为5 DH yv^
//default value of nSplitter is 5 2t9UJu4
this("","","",5); :Y\ ~[Y
} **L&I5Hhm
pX{wEc6}
jwT` Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CYLab5A
{ N.vWZ7l8
sSiteURL= sURL; zXx/\B$&d*
sFilePath = sPath; fJ[ ^_,O
sFileName = sName; m~5 unB9
this.nSplitter = nSpiltter; Cd_@<
Ai1"UYk\\Y
9gcW;
} XZb=;tYo
o6px1C:
@T~XwJ~
public String getSSiteURL() dazNwn
{ LNWS
return sSiteURL; v*?8:>:}
} JFVx&
1hY|XZ%qd
| J3'#7
public void setSSiteURL(String value) 7h}gIm7e"
{ >)u;X
sSiteURL = value; D{6y^@/
} ?"mZb#%
lc[6Mpi7s[
nsRCDUCi
public String getSFilePath() xqzeBLU
{ .DhI3'Jrl
return sFilePath; @01.Pd
} iHGVR
A.vAk''(}+
VKDOM0{V
public void setSFilePath(String value) P}}G9^
{ d\JaYizp
sFilePath = value; ^)~Smj^d
} Eo6N'h>h
'vd&r@N
|@u2/U9
public String getSFileName() O~*i_t*i9{
{ miaH,hm
return sFileName; \Nt 5TG_
} K9#kdo1 2
?Ts]zO%%Z
Gk*u^J(
public void setSFileName(String value) IQPu%n{0v
{ R^.PKT2E
sFileName = value; &))d],tJX
} YCD|lL#
%]_: \!
7HDc]&z
public int getNSplitter() Ojc Tu
{ + +}!Gfc?s
return nSplitter; $Y|OGZH8E
} x"Ky_P~
; BN81;
~a([e\~
public void setNSplitter(int nCount) ed,A'S=d
{ T/3LJGnY
nSplitter = nCount; vTK%4=|1}!
} }ssV"5M
} >[;W~*
-wXeue},>
Mp`$1Ksn
/* &u2;S?7m
**Utility.java ,p d-hu
*/ A3a//e
package NetFox; qLmzA@Cv
m !*F5x
BYq80Vk%@
public class Utility { mKZzSd)p
eTa_RO,x
,ErfTg&^
public Utility() 1,wcf,
{ ddfGR/1X
^aSb~lce
-Q n-w3~&
} 9>~pA]j%
,W}:vdC
//线程睡眠 ( V4Ppg
public static void sleep(int nSecond) dipfsH]p
{ %]4Tff
try{ ,m=G9QcN
Thread.sleep(nSecond); EB[T 5{
} N(7XILC
catch(Exception e) Z\nDR|3
{ pN[WYM?[
e.printStackTrace (); vha9,5_
} xsH1)
} M@cFcykK
|T|m5V'l
//日志 CeYhn\m5K0
public static void log(String sMsg) 4-yK!LR
{ CVfV
System.err.println(sMsg); e34>q:#5l
} :0r,.)
e=0]8l>\V
zKd@Ab
public static void log(int sMsg) XDY]LAV
{ U!(.i1^n
System.err.println(sMsg); Hh%!4_AMw
} /pj[c;aO
} J~2SGXH)^?
9hA`I tS
hp~q!Q1=
/* cU6*y!}9
**TestMethod.java B]X8KzLu
*/ B7 s{yb
package NetFox; B->AY.&j
4C*ywP
''nOXl
public class TestMethod { h$02#(RHJ
)=5&Q
Pu3oQDldV
public TestMethod() [~9UsHfH
{ ///xx/weblogic60b2_win.exe h!w::cV
try{ g6,DBkv2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |[.-pA^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]*=4>(F[
SiteFileFetch fileFetch = new SiteFileFetch(bean); gA2Wo+\^bq
fileFetch.start(); JIySe:p3
} ^ }7O|Y7
catch(Exception e){e.printStackTrace ();} A8m06
1$&@wG
L_Ok?9$
} \qG?'Iy
bIU.C|h@
p[Po*c.b
public static void main(String[] args) hP"2X"kz&
{ >5FTBe[D
new TestMethod(); :H]d1
} 4#IT" i
} ng%[yY
点击下载更多相关资料