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)); & ?/h5<
} 9Vzk:zOT
for(int i=0;i<nEndPos.length-1;i++) s.1(- "DU
{ TmKO/N@}
nEndPos = nStartPos[i+1]; BS*cG>T
} XT{1!I(
nEndPos[nEndPos.length-1] = nFileLength; 6]T02;b>/,
} 4dMwJ"V
} 3=t}py7M
>G' NI?$
`C=!8q
//启动子线程 dulW!&*No
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $msT,$NJ
for(int i=0;i<nStartPos.length;i++) da\K>An>
{ 5ez"B]&T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5zpk6FR$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $Y$!nPO
nStartPos,nEndPos,i); 2s-f?WetbP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i= ~HXr}
fileSplitterFetch.start(); jA=uK6m
} n.$<D[@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )K@ 20Q+0K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gD=s~DgN)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m f4@g05
nEndPos = " + nFileLength); s=q\BmG
// fileSplitterFetch[nPos.length-1].start(); 1uB}Oe2~
Zdh4CNEeFP
zZDG5_$n
//等待子线程结束 .w$v<y6C
//int count = 0; rcxV ,<[B
//是否结束while循环 ~Ufcy{x#
boolean breakWhile = false; &_" 3~:N8k
&HFMF)NA
#%k5s?cP@
while(!bStop) t=XiSj\n
{ WRVKh
write_nPos(); Fj1/B0acS
Utility.sleep(500); %|SbZ)gcQ
breakWhile = true; ,>{4*PM(
"^_p>C)T
^%go\ C ;
for(int i=0;i<nStartPos.length;i++) wjS3ItB
{ 8Y5* 1E*
if(!fileSplitterFetch.bDownOver) rRT9)wDa
{ b\=0[kBQw
breakWhile = false; ,"h$!k"$g
break; `*}#Bks!
} CFul_qZ/e
} htM5Nm[g
if(breakWhile) bGK&W;Myk
break; 0R_ZP12
OMKEn!Wq
J4`08,
//count++; 5uDQ*nJ|
//if(count>4) *>_:E6)
// siteStop(); O(&EnNm[2
} \VtCkb
uAVV4)
Q=e?G300#L
System.err.println("文件下载结束！"); 71K6] ~<
} ]PUyX8'~
catch(Exception e){e.printStackTrace ();} T]CvfvO5
} @|-ydm0
{zVJlJKxs
Oo7n_h1
//获得文件长度 G92=b*x/
public long getFileSize() EVb'x Zr
{ ,wX/cUyZ
int nFileLength = -1; d:A+s>`$M
try{ +"'h?7'C
URL url = new URL(siteInfoBean.getSSiteURL()); NNe'5q9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z W+wtYV4
httpConnection.setRequestProperty("User-Agent","NetFox"); k9}im
tp5]n`3rD
%A82{
int responseCode=httpConnection.getResponseCode(); NKGo E/
if(responseCode>=400) :+E>UzT
{ %}j/G l5
processErrorCode(responseCode); [c>X Q
return -2; //-2 represent access is error _;'}P2&Q
} `awk@
QZh8l-!#5
dR$P-V\y`%
String sHeader; o"[qPZd>
CZ]+B8Pl(x
/3Se*"u
for(int i=1;;i++) +pf 7
{ B"+Ygvxb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Nkv2?o>l
//Utility.log(in.readLine()); A\4Gq
sHeader=httpConnection.getHeaderFieldKey(i); $#KSvo{otI
if(sHeader!=null) >Pv%E
{ dZnq 96<:|
if(sHeader.equals("Content-Length")) N.&)22<m9
{ uidE/7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6GJ?rE E/
break; YjHGdacs
} \9ap$
} ig?]kZ
else It]CoAo+
break; ]&}?J:+?0E
} <Xl G:nmY
} 4=q\CK2^A
catch(IOException e){e.printStackTrace ();} (/qY*?
catch(Exception e){e.printStackTrace ();} J3q}DDnEo
o<C~67o_
]t#,{%h
Utility.log(nFileLength); 4<lZ;M"
1%1-j
3FNj~=N
return nFileLength; r/{0YFa
} t$Qav>D
={zYcVI
-sc@SoS
//保存下载信息（文件指针位置） [$] JvF
private void write_nPos() C #TS
{ Nk^#Sa?
try{ /]+t$K\cBq
output = new DataOutputStream(new FileOutputStream(tmpFile)); .5ingB3%
output.writeInt(nStartPos.length); (F_#LeJ|
for(int i=0;i<nStartPos.length;i++) g00XZ0@
{ H 5sj% v
// output.writeLong(nPos); bZtjg
output.writeLong(fileSplitterFetch.nStartPos); Mb$&~!
output.writeLong(fileSplitterFetch.nEndPos); "]JS,g {m
} )0UQy#r
output.close(); O"Xjv`j:
} p&ZD1qa
catch(IOException e){e.printStackTrace ();} (U|W=@8`
catch(Exception e){e.printStackTrace ();} ,Hj=]e2?
} lW>bXC
V$:v~*Y9
DoImWNLo
//读取保存的下载信息（文件指针位置） kyY tL_SD
private void read_nPos() RYvS,hf6z
{ -ud!j
try{ /B1NcRS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2+ 9">a@
int nCount = input.readInt(); *,Y+3yM
nStartPos = new long[nCount]; Y|1kE;
nEndPos = new long[nCount]; MNJ$/l)h
for(int i=0;i<nStartPos.length;i++) L0uN|?}
{ >nTGvLOq
nStartPos = input.readLong(); \idg[&}l}
nEndPos = input.readLong(); n{UB^-}5
} 8+GlM+>4
input.close(); F!SmCE(0x
} {)k}dr
catch(IOException e){e.printStackTrace ();} ((t8
catch(Exception e){e.printStackTrace ();} t@!oc"z}@
} HYpB]<F
8[zP2L!-
]1p&*xX:Bj
private void processErrorCode(int nErrorCode) A:;KU
{ u^:!!Suo
System.err.println("Error Code : " + nErrorCode); $Cf_RFH0
} uWMAXGL
8|i&Gbw+
x2K.5q>
//停止文件下载 )8e_<^M
public void siteStop() xT=|Uc0
{ w3yI;P
bStop = true; [g<6i.<I
for(int i=0;i<nStartPos.length;i++) 0~^opNR
fileSplitterFetch.splitterStop(); 8HTV"60hTs
oYqlN6n,=6
^#"!uCq]gM
} oOJN?97!k
} yNI}=Z
//负责部分文件的抓取 rY($+O@a<
**FileSplitterFetch.java x~Pv
*/ ^WM)UZEBC
package NetFox; %]
?M\3n5;
BIX%Bu0'f
import java.io.*; LI(Wu6*Y
import java.net.*; Yo:>m*31
-bKli<C
59ro-nA9v
public class FileSplitterFetch extends Thread { 7?cZ9^z`w
xt40hZ$
Oja)J-QXb
String sURL; //File URL mDj:w#q
long nStartPos; //File Snippet Start Position dr:)+R
long nEndPos; //File Snippet End Position V&NOp
int nThreadID; //Thread's ID |QxDjL<&t4
boolean bDownOver = false; //Downing is over G?8,&jP~T
boolean bStop = false; //Stop identical CXJ0N
FileAccessI fileAccessI = null; //File Access interface Ku&0bXP
6C) G
v>0xHQD*<M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException TX8,+s+
{ @\[&_DZ
this.sURL = sURL; %.[GR
this.nStartPos = nStart; >dZ x+7
this.nEndPos = nEnd; eGnc6)x@C
nThreadID = id; 0}HKmEM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ks'25tv}F
} SOeL@!_
v#D9yttO{
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public void run() 30[?XVI&
{ H VG'v>s@
while(nStartPos < nEndPos && !bStop) KqaeRs.u
{ aoMQ_@0
hC5ivJ
GQ)hZt0
try{ Fc42TH p
URL url = new URL(sURL); [nYwJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IXX^C}\,
httpConnection.setRequestProperty("User-Agent","NetFox"); Z/56JYt!~
String sProperty = "bytes="+nStartPos+"-"; #!9aTp).AL
httpConnection.setRequestProperty("RANGE",sProperty); B||^sRMX
Utility.log(sProperty); 1<fEz
'{U56^b]
d) G7U$z~
InputStream input = httpConnection.getInputStream(); 4$ejJaE
//logResponseHead(httpConnection); "hpK8vQ
tse(iX/D
aI+:rk^
byte[] b = new byte[1024]; 8pt;''
int nRead; Y@RPQPmIQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _vvnxG!x&
{ h^34{pKDn
nStartPos += fileAccessI.write(b,0,nRead); Y.jg }oV
//if(nThreadID == 1) jw#'f%*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9 `J`(
} s`GSc)AI
l0[jepmpiT
u`K+0^)T`
Utility.log("Thread " + nThreadID + " is over!"); &bnF{~<\
bDownOver = true; 7P!/jawxb
//nPos = fileAccessI.write (b,0,nRead); `%F.]|Y0
} Qe]@`Vg
catch(Exception e){e.printStackTrace ();} Vx-HW;,
} 1 dI
} o&gcFOM22
wxr93$v
}"Y]GH4Y
//打印回应的头信息 nN/v7^^
public void logResponseHead(HttpURLConnection con) A3yVT8
{ A$fd6+{
for(int i=1;;i++) 6$@Pk<w
{ rb&^ei9B
String header=con.getHeaderFieldKey(i); 6Z|/M6f
if(header!=null) &l{yEWA}g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %^gT.DsX-
Utility.log(header+" : "+con.getHeaderField(header)); !tHqF
else u.8vXc
break; ;z)$wH0xc
} w0tlF:Eg
} c3i|q@ k
e+4p__TmZ
^/mQo`[G
public void splitterStop() : bT*cgD{
{ 8r)eiERv
bStop = true; ?i)-K?4Sb
} BxO2w1G
u\&oiwSIP
n4(w?,w}
} ANp4yy+
W[j =!o
9j$ OU@N 8
/* H>;km$b +
**FileAccess.java mkrvWZjZX
*//文件访问(定位，写) BAg*zYV7
package NetFox; ]n\WCU]0
import java.io.*; Fov/?:f$
t*e+[
noh3mi
public class FileAccessI implements Serializable{ {3`#? q^o'
B;hc|v{(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0%`\8
RandomAccessFile oSavedFile; f9&D0x?
long nPos; Mwp#.du(
xgsD<3
bq<QUw=]q&
public FileAccessI() throws IOException "p2 $R*ie
{ v#YO3nD
this("",0); +*!oZKm.
} H&3VPag
_Vj O [hx
:[|`&_D9J
public FileAccessI(String sName,long nPos) throws IOException ^?&Jq_oU
{ :]=Y1*L\)
oSavedFile = new RandomAccessFile(sName,"rw"); -md2Z0^ Kc
this.nPos = nPos; 7b:oz3?PI
oSavedFile.seek(nPos); ;&;coH8`
} X\X
=n9adq
5j{o0&=_$
public synchronized int write(byte[] b,int nStart,int nLen) {B?%r[nW
{ 06 K8|K
int n = -1; 4#;rv$ {
try{ T!(I\wz;Bo
oSavedFile.write(b,nStart,nLen); vlp]!7v
n = nLen; 7<|1 xOT
} A$Es(<'9g
catch(IOException e) V4/P
{ v?fB:[dG
e.printStackTrace (); Y@M=6G
} w v9s{I{P
f==o
[$8*(d"F'
return n; 2"yzrwZ:
} D#W{:_f
n_.2B$JD
j4ypXPY``!
} s2b!Nib
?n\~&n'C
@<W"$_r-
/* K]N^6ome
**SiteInfoBean.java 6\OSIxJZF
*/ `:i|y
package NetFox; K)l{3\9l|
"*kWM
Vy16Co
public class SiteInfoBean { qECc[)B
onG,N1`+
u?Iop/b
private String sSiteURL; //Site's URL +g7Iu! cA
private String sFilePath; //Saved File's Path Q%o
private String sFileName; //Saved File's Name ,Xo9gn
private int nSplitter; //Count of Splited Downloading File @UkcvhH
e0(loWq]
PPPRO.y
public SiteInfoBean() (<itE3P
{//nSplitter的缺省值为5 ]/JE#
//default value of nSplitter is 5 [q9TTJ@2
this("","","",5); A6q,"BS^d
} f.V0uBDN
qaG%PH}a
1S 0GjR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *ZKfyn$+~
{ &p=|z2 J
sSiteURL= sURL; F!c%&Z
sFilePath = sPath; x>&1;g2r
sFileName = sName; TnPdpynP
this.nSplitter = nSpiltter; HPVT$EJ
oopTo51,a
$T1 D ?X
} $-5iwZ
W{=>c/
5p U(A6RtS
public String getSSiteURL() O0WzDD
{ &nZ=w#_
return sSiteURL; &>i+2c~
} {LR?#.
L a0H
NZi5rXN
public void setSSiteURL(String value) - FA#hUK$
{ sJt&`kZ
sSiteURL = value; |Wi$@sWO
} S%mN6b~{
+]`MdOu
X<,sc;"b`k
public String getSFilePath() Lo7R^>
{ yY`<t
return sFilePath; jVi''#F?f
} ~Jmn?9 3
UZmzk
py P5^Qv
public void setSFilePath(String value) !_l W#feR
{ ]Ol@^$8}
sFilePath = value; O'$0K0k3
} g2:^Z==
hb_YdnG
G80d!*7
public String getSFileName() Ax=Rb B"
{ 4K[U*-\"
return sFileName; ,Z&"@g
} j= ]WAjT
\W??`?Idh
Hd2Sou4-j
public void setSFileName(String value) ~iEH?J%i1r
{ SZK~<@q5
sFileName = value; .CQ IN]iD
} 0qw,R4YK
N}>`Xm5'
,t*#o&+
public int getNSplitter() fo4j^,`
{ VAsaJ`vcb
return nSplitter; Y;xVB" (
} $N+a4
%CD}A%~
vxk1RL*Xu
public void setNSplitter(int nCount) WP2|0ib
{ (!W:-|[K\
nSplitter = nCount; $MB56]W8
} B07(15y]
} gqyQ Zew
%I&Hx<Hj
0)yvyQ5
/* nd'zO#"m?
**Utility.java Vyu0OiGcR
*/ M:Xswwq
package NetFox; iN<&
pRPz1J$58
g[q1P:I@W
public class Utility { D!TS/J1S;u
<M7@JgC &
EAj2uV
public Utility() ^qS[2Dy
{ 1;]cYIq
MftX~+
F>96]71 2
} qZ6P(5X
w[~$.FM/
//线程睡眠 v&xk?F?WU,
public static void sleep(int nSecond) X<#Q~"
{ m~(]\
try{ k=o>DaEh(
Thread.sleep(nSecond); fL7u419=
} v!b 8_0~u6
catch(Exception e) wWU5]v
{ `4N{x.N
e.printStackTrace (); $F,&7{^
} !"e~HZmr
} :a#pzEK
kk*:S*,
//日志 zLa3Q\T
public static void log(String sMsg) yavoGk
{ A7SE>e>
System.err.println(sMsg); 7KzMa%=
} 1; "t8.*%e
AHA4{Zu[
i$Sq.NU
public static void log(int sMsg) ]XAJ|[]sj*
{ ggR--`D[
System.err.println(sMsg); 0D*uZ,oBEw
} Q4&|^RLLG
} 5v uB87`
[3#A)#kWm
ydyGPZt
/* ~SW_jiKM
**TestMethod.java Qf}^x9'
*/ VZJ[h{ 6
package NetFox; (DW[#2\.
c T!L+zg
l6C^,xU~IX
public class TestMethod { TBzOz:k
,z1fiq
{D(_"
public TestMethod() bBFdr
{ ///xx/weblogic60b2_win.exe j+_pF<$f:
try{ $YyN-C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K^_Mt!%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^.d97rSm
SiteFileFetch fileFetch = new SiteFileFetch(bean); c<8RRYs
fileFetch.start(); ThLnp@
} "^~>aVuXf
catch(Exception e){e.printStackTrace ();} ZN:~etd
&$vW
~x>?1K
} ZXf^HK
F_Q?0 Do0'
.i7bI2^
public static void main(String[] args) gGiLw5o,
{ WaVP+Ap
new TestMethod(); ?}N@bsl08w
} )7e[o8O_6
} t^=6czk
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