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)); F)fCj^zL
} _:dt8+T#
for(int i=0;i<nEndPos.length-1;i++) =QdHji/sB
{ RRSkXDU}
nEndPos = nStartPos[i+1]; W5 l)mAv
} iczJXA+
nEndPos[nEndPos.length-1] = nFileLength; vNdMPulr{
} <'(O0
} ~x67v+I
$z1W0
sKE7U>mz|
//启动子线程 GJTKqr|1O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (]cM;
for(int i=0;i<nStartPos.length;i++) VtM:~|v
{ )|52B;yZx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 87&BF)]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W^U6O&-K
nStartPos,nEndPos,i); kdmmfw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :Q\Es:y
fileSplitterFetch.start(); YoC{ t&rY
} Cn\5Vyrl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h>0R!Rl8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r0MUv}p#|L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =yT3#A~<G
nEndPos = " + nFileLength); R1,.H92
// fileSplitterFetch[nPos.length-1].start(); k&JB,d-mJ%
*\gS 2[S
gc5u@(P"
//等待子线程结束 ;Gf,I1d}{
//int count = 0; ^)i5.o\
//是否结束while循环 :eHD{=
boolean breakWhile = false; A(Tqf.,G
i^<P@ |q
K;ncviGu
while(!bStop) [u?*' c{
{ cx+w_D9b!
write_nPos(); tccw0
Utility.sleep(500); ,=Q;@Z4 vJ
breakWhile = true; /R/\>'{E&c
$*k(h|XfwW
Kivr)cIG
for(int i=0;i<nStartPos.length;i++) U3UKu/Z
{ |gV$ks\<
if(!fileSplitterFetch.bDownOver) )># Y,/q
{ *8I+D>x
breakWhile = false; #\P\(+0K
break; ]TE(:]o7V
} DJWm7 t
} O {hM
if(breakWhile) !sTOo
break; W't?aj I|
K^zu{`S
i>*|k]
//count++; wSV}{9}wr%
//if(count>4) /JcfAY
// siteStop(); ~8oti4
} 8D H~~by
Sa8KCWgWh
U{`Q_Uw@$:
System.err.println("文件下载结束！"); 7%MD0qm-
} e7O9q8b
catch(Exception e){e.printStackTrace ();} MbT;]Bo
} p1BMQ?=($
MBIlt 1P
tfAO#htq
//获得文件长度 1QA{NAnu&
public long getFileSize() R>C^duos.
{ <2.87:
int nFileLength = -1; /r8'stRzv
try{ og?>Q i Tr
URL url = new URL(siteInfoBean.getSSiteURL()); -22]|$f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $.5f-vQp
httpConnection.setRequestProperty("User-Agent","NetFox"); c4Leh"ry
:cE6-Fv
}CM</
int responseCode=httpConnection.getResponseCode(); av8\?xmo.$
if(responseCode>=400) -%G}T}"_
{ uY_vX\;67z
processErrorCode(responseCode); ?'8(']/
return -2; //-2 represent access is error VG=mA4Dd
} %"jp':
m)1+D"z
RE<s$B$[
String sHeader; uHQf<R$:
\@8.BCWK
Gi+ZI{)
for(int i=1;;i++) v'e5j``=
{ 2=%R>&]*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >WZ_) `R
//Utility.log(in.readLine()); Ovhd%qV;Y
sHeader=httpConnection.getHeaderFieldKey(i); ! N!A%
if(sHeader!=null) 0XzrzT"&
{ uE=pq<
if(sHeader.equals("Content-Length")) c$fYK
{ ~lQ<#*wl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~Qm<w3oy
break; = }!4%.$
} EpCT !e
} *dpKo&y
else v;ZIqn"
break; - %'ys
} isR)^fI|
} h?-*SLT
catch(IOException e){e.printStackTrace ();} P 5_l&
catch(Exception e){e.printStackTrace ();} oD8X]R, H
.kqH}{hf
N]dsGvX
Utility.log(nFileLength); %NH{%K,
l\DcXgD x
Q~-MB]'
return nFileLength; RQ*oTsq
} O?OG`{k
U?e.)G
$v\o14v
//保存下载信息（文件指针位置） !?aL_{7J
private void write_nPos() K?]c
{ ',l}$]y5
try{ d) $B
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7H$wpn Zln
output.writeInt(nStartPos.length); 9k*1_
for(int i=0;i<nStartPos.length;i++) Mrly(*!U"@
{ sIz*r Gz
// output.writeLong(nPos); :YUQKy
output.writeLong(fileSplitterFetch.nStartPos); GS qt:<Qs
output.writeLong(fileSplitterFetch.nEndPos); V+>.Gf
} pRc<U^Z.h
output.close(); =%ry-n G
} P+gYLX8
catch(IOException e){e.printStackTrace ();} N6<G`k,
catch(Exception e){e.printStackTrace ();} \sc's7
} >mCS`D8
egn9O
iZ;y(
//读取保存的下载信息（文件指针位置） m[$pj~<\
private void read_nPos() %<yH6h*u
{ }HLV'^"k
try{ )Q5ja}-{V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |HfN<4NL
int nCount = input.readInt(); eZvG
nStartPos = new long[nCount]; uD8,E!\
nEndPos = new long[nCount]; %$ ^eY'-'
for(int i=0;i<nStartPos.length;i++) }pOJM&I
{ qu+Zl1~$]
nStartPos = input.readLong(); LQDU8[-
nEndPos = input.readLong(); S&z8-D=8k
} bo_Tp~j
input.close(); sA:k8aj
} nS9 kwaO
catch(IOException e){e.printStackTrace ();} BWev(SF{Ny
catch(Exception e){e.printStackTrace ();} W_FN*Er
} !K8V":1du#
)ad6>Y
T(q/$p&q
private void processErrorCode(int nErrorCode) w#w?Y!JXo
{ ){FXonVP
System.err.println("Error Code : " + nErrorCode); u0i;vO)MNt
} w<$0n#5
v?<Tkw ^F
"3e1 7dsY
//停止文件下载 2&KM&NX~
public void siteStop() 2E_d$nsJ
{ ~`!{5:v
bStop = true; 9`|~-b
for(int i=0;i<nStartPos.length;i++) o?((FW5.;
fileSplitterFetch.splitterStop(); <:!;79T\
ODyKS;
t<H@c9{;*
} DEN (pA\
} ^hyp}WN
//负责部分文件的抓取 :#nv:~2]
**FileSplitterFetch.java PsOu:`=r
*/ h%+6y
package NetFox; O]-s(8Oo3
x!;;;iS
$Y=xu2u)
import java.io.*; 5"^Z7+6
import java.net.*; z8*{i]j
4u+4LB*
D\ kd6
public class FileSplitterFetch extends Thread { 2y#[uSqB
M0Vs9K=
Ns5'K^
String sURL; //File URL SE0&CV4
long nStartPos; //File Snippet Start Position ]h4r@L3
long nEndPos; //File Snippet End Position =b/:rSd$NA
int nThreadID; //Thread's ID y25L`b
boolean bDownOver = false; //Downing is over -;W`0k^
boolean bStop = false; //Stop identical S0jYk(
FileAccessI fileAccessI = null; //File Access interface P>[,,w
c^W \0
6sz:rv}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OTV$8{
{ /4%ycr6
this.sURL = sURL; @zq]vX-A_
this.nStartPos = nStart; Mcm%G#
this.nEndPos = nEnd; ~X<Ie9m1x
nThreadID = id; Cs?[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Lf0Wc'9{
} E`gUNAKQ
1# ;`1i
(\*+HZ`(Uu
public void run() hVf;{p &
{ P`]p&:
while(nStartPos < nEndPos && !bStop) {L.=)zt>
{ tEjT$`6hp
D!5{CQl
C)qy=lx%
try{ l2 mO{'|C
URL url = new URL(sURL); dH_g:ocA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3}gf%U]L
httpConnection.setRequestProperty("User-Agent","NetFox"); vq-#%o
String sProperty = "bytes="+nStartPos+"-"; CCp&+LRvR
httpConnection.setRequestProperty("RANGE",sProperty); JH`oa1b
Utility.log(sProperty); < +X,oxg
wgFAPZr
N5jJ,iz
InputStream input = httpConnection.getInputStream(); tVqc!][
//logResponseHead(httpConnection); m$WN"kV`,9
%mr6p}E|
84jA)
byte[] b = new byte[1024]; .u\xA7X
int nRead; _8ubo\M~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /& wA$h
{ /@feY?glc
nStartPos += fileAccessI.write(b,0,nRead); &)GlLpaT
//if(nThreadID == 1) 5rlZ'>I.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s8|Fe_
} @8"cT-
d[$YTw
O#3PUuE%d
Utility.log("Thread " + nThreadID + " is over!"); f0]`TjY
bDownOver = true; r0j+P%
//nPos = fileAccessI.write (b,0,nRead); _>4Qh#6K
} @zi_@B
catch(Exception e){e.printStackTrace ();} tr-muhuK
} Dh.pH1ZY3n
} Eq6. s)10
,*j@Zb_r
/6yH ,{(a
//打印回应的头信息 'm|PSwB7
public void logResponseHead(HttpURLConnection con) z\r29IRh
{ At)\$GJ
for(int i=1;;i++) m(p0)X),_i
{ :!<U"AC
String header=con.getHeaderFieldKey(i); Rb l4aB+
if(header!=null) qY$]^gS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *7G5\[gI$
Utility.log(header+" : "+con.getHeaderField(header)); WYY&MHp
else [$FiXH J
break; 4">C0m;ks
} JxLSQ-"
} p$1y8Zbor
H0?Vq8I?
BX-fV|
public void splitterStop() {mmQv~|5q
{ |tdsg
bStop = true; z%~rQa./$
} ^_!2-QY.~
H-5h-p k
F|^tRL-
} }e0>Uk`[
66Bx,]"6
h7cE"m
/* 2R>!Wj'G+o
**FileAccess.java DhzmC
*//文件访问(定位，写) Tv /?-`Y
package NetFox; 8Q\ T,C
import java.io.*; K\y W{y1
DE!P[$J
08F~6e6a8
public class FileAccessI implements Serializable{ I6RF;m:Jw
bm#/ KT_8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Yrmd hSY
RandomAccessFile oSavedFile; PIZK*Lop
long nPos; KAR **Mp+
#s3R4@{
JYO("f
public FileAccessI() throws IOException A? T25<}
{ v/~Lfi
this("",0); FN"Ye*d
} #Z1 <lAy
*rv7#!].
MoMxKmI
public FileAccessI(String sName,long nPos) throws IOException *(CV OY~
{ $[{YE[a
oSavedFile = new RandomAccessFile(sName,"rw"); 7Kn}KO!Y8
this.nPos = nPos; uE-|]QQo
oSavedFile.seek(nPos); ~U<=SyZYo
} WIYWql>*
xa$4P [
B)=)@h[f
public synchronized int write(byte[] b,int nStart,int nLen) Uo=_=.GQ
{ Tjj-8cg
int n = -1; 9Z lfY1=
try{ eh}I?:(a?
oSavedFile.write(b,nStart,nLen); cs7K^D;.V
n = nLen; G}#p4\/
} :[!b";pR
catch(IOException e) ]Ia}H+&
{ RLR\*dL1
e.printStackTrace (); Z^6qxZJ7
} @ w?,7i-S
m)e~HP7M
l?:S)[:
return n; mae@L
} HL~DIC%
M{Hy=:K+
mG.H=iw
} J>Bc-%.Q
]7J*(,sp
|^C35 6M>
/* bEli!N$
**SiteInfoBean.java W #V`|JA
*/ ~%QI#s?|
package NetFox; _FP'SVa}D
tqzr+
O>[B"mMt
public class SiteInfoBean { KZ$^Q<d^
?9ScKN
u$ff %`E
private String sSiteURL; //Site's URL g^[BnP)I
private String sFilePath; //Saved File's Path i9v|*ZM"
private String sFileName; //Saved File's Name b/obHB+:
private int nSplitter; //Count of Splited Downloading File A+ LX37B
} bm ^`QY
i^}ib RQbN
public SiteInfoBean() CSlPrx2\
{//nSplitter的缺省值为5 1-}M5]Y
//default value of nSplitter is 5 2k+u_tj>
this("","","",5); ->`R[k
} q" @%WK
Bj* M W
]. 0;;v6)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aPm2\Sq$
{ D|g{]nO
sSiteURL= sURL; J7p?9
sFilePath = sPath; Vw+RRi(
sFileName = sName; +k\cmDcb
this.nSplitter = nSpiltter; }TRVCF1
A 1B_EX.
!xE@r,'oN
} `c?8i
5Yr$tl\k
bFsJqA.A
public String getSSiteURL() }xpo@(e
{ Ti$_V_
return sSiteURL; XvIY=~
} <`d;>r=4z
lf}%^od~6
FQM9>l@6)>
public void setSSiteURL(String value) jf=\\*64r4
{ E(Zm6~
sSiteURL = value; zXML<?w
} Ir6g"kwCKq
8K2=WYN
Le*gdoW.
public String getSFilePath() G-5ezVli
{ h I7ur
return sFilePath; i/RA/q
} (w-@b70E
^1;Eq>u
A$-\Er+f
public void setSFilePath(String value) }NKnV3G/Z
{ S^A+Km3VB
sFilePath = value; 0ni/!}YP_
} p{[(4}ql
tgC)vZ&a
9{8xMM-
public String getSFileName() h@fF`
{ AtNF&=Op
return sFileName; JzmX~|=Xi
} oW3|b2D
m-lTXA(
<v3pI!)x
public void setSFileName(String value) @.} @K
{ m.Ki4NUm
sFileName = value; lQ#='Jqfp
} !7Nz_d~n
W|\$}@>
Ca ?d8
public int getNSplitter() FTWjIa/[
{ Kon|TeC>d
return nSplitter; g9gi7.'0
} remRmY?
T+41,
$Z<x r
public void setNSplitter(int nCount) YRu#JYti
{ ,$Xhwr
nSplitter = nCount; uLSuY}K0
} Y=Om0=v
} /]-a 1
\WxBtpbQB
|>KOlwh5n
/* ,PeE'$q
**Utility.java </D )i
*/ 6UM1>xq9A
package NetFox; UdcrX`^.
gl 27&'?E*
-l?\hmDl
public class Utility { $8`"
SE6c3
7KN+ @6!x
public Utility() mX[J15
{ {_UOS8j7
e*M-y C
,O_iSohS
} 1 Q*AQYVY
JC iB;!y
//线程睡眠 fndbGbl8p
public static void sleep(int nSecond) RaOLy \
{ ~L:H]_8F l
try{ =s&ycc;-5}
Thread.sleep(nSecond); F8|m i`f-
} 2yV^'o)
catch(Exception e) P4fnBH4OQ
{ mI5!rrRD|
e.printStackTrace (); 2^y*O
} yiMqe^zy
} .JV y}^Q\
Rd[^)q4d$w
//日志 Y(=A HmR
public static void log(String sMsg) Qcn;:6_&W
{ ,,]<f*N
System.err.println(sMsg); wK0],,RN,h
} ~>XqR/v
NRazI_Z
(Ta(Y=!uq
public static void log(int sMsg) Wpc8T="q
{ %:Z_~7ZR
System.err.println(sMsg); yw >Frb5p
} Ho1V)T>
} ANTWWs}
7m8(8$-6
eVj7%9
/* 6eb~Z6n&?
**TestMethod.java f dJ<(i]7W
*/ 5]K2to)>`
package NetFox; !\!j?z=O8
hGRHuJ
q4Mv2SPT
public class TestMethod { m .R**g
0+/ew8~$
o{3>n"\w3
public TestMethod() ._q<~_~R
{ ///xx/weblogic60b2_win.exe ?hYWxWW
try{ J3$@: S'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pA6A*~QE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QW_BT^d"
SiteFileFetch fileFetch = new SiteFileFetch(bean); 49YN@PXC
fileFetch.start(); *Tr9pq%m
} B+MnT{
catch(Exception e){e.printStackTrace ();} KxDp+]N]
AWd,qldv
nO#x"
} e-#Vs{?|r
+[}<u--
k; >Vh'=X
public static void main(String[] args) D4sp+
{ <6+T&Ov6
new TestMethod(); 7"1]5\p^g
} $g),|[x+(
} `pF7B6[B
点击下载更多相关资料