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)); $|7=$~y
} X|/RV4x@Cq
for(int i=0;i<nEndPos.length-1;i++) Ptcq/f
{ fmJK+
nEndPos = nStartPos[i+1]; w^=(:`
} 54B`T/>R:E
nEndPos[nEndPos.length-1] = nFileLength; ZJ~0o2xZ'
} .z=%3p8+
} uc}tTmB|
U&{w:P
8aC=k@YE
//启动子线程 CBNt _y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mIp> ~
for(int i=0;i<nStartPos.length;i++) sdiWQv
{ mq:WBSsV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), US=K}B=g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K:kb&W
nStartPos,nEndPos,i); dG8mE&$g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c5uC?b].
fileSplitterFetch.start(); *4LRdLMn
} /Oi(5?Jn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z{:;LC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XT*/aa-1'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |z"$^|@d?
nEndPos = " + nFileLength); [b&V^41W
// fileSplitterFetch[nPos.length-1].start(); J7C?Z
x!vyjp
<L11s%5-
//等待子线程结束 /hmDePo}
//int count = 0; ~-y&C%
//是否结束while循环 sa _J6~
boolean breakWhile = false; MX?UmQ'
AAW] Y#UwW
s;E(51V<>
while(!bStop) Xit@.:a;
{ Nd_A8H,&B
write_nPos(); ~c] q:pU2
Utility.sleep(500); r[T(R9k
breakWhile = true; ){z#Y#]dP
Fw{68ggk
8SLE*c^8
for(int i=0;i<nStartPos.length;i++) 8DMqjt3B
{ $G6kS@A
if(!fileSplitterFetch.bDownOver) %'=2Jy6h
{ 2{Dnfl'k
breakWhile = false; LFqY2,#i
break; [s\8@5?E
} #_`p 0wY
} %Y0BPTt$
if(breakWhile) avM8-&h
break; )4-!]NsV
#H<}xC2
LAM{ ,?~
//count++; W(Md0*
//if(count>4) K'e,9P{
// siteStop(); tZm`(2S
} l:bbc!3
e==/+
8B-mZFXpK
System.err.println("文件下载结束！"); 'p\&Mc_Gu
} Cg%Owe/E?0
catch(Exception e){e.printStackTrace ();} $T:;KcW)
} [` }w7
PFx.uqp
2L[!~h2
//获得文件长度 0VNpd~G$
public long getFileSize() gR gB= C{
{ c`hENPhW
int nFileLength = -1; zHg=K /
try{ 7HY8 F5Brx
URL url = new URL(siteInfoBean.getSSiteURL()); tS5J{j>T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZR%$f-
httpConnection.setRequestProperty("User-Agent","NetFox"); :xq{\"r
[\ Sd*-
+4Wl
int responseCode=httpConnection.getResponseCode(); 1JdMw$H
if(responseCode>=400) \CE+P5
{ s]`6uyW"
processErrorCode(responseCode); 2M\7j
return -2; //-2 represent access is error #`=>Mza
} 6/Yo0D>M$
\ZhkOl
0S4Y3bac&
String sHeader; n[qnrk*3 %
/.rj\,
5D?{dA:Rq
for(int i=1;;i++) 0bJT0_
{ X(17ESQ/Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \6.dGKK
//Utility.log(in.readLine()); ,'t&L]
sHeader=httpConnection.getHeaderFieldKey(i); F Pjc;zNA
if(sHeader!=null) (fr=[m$`
{ iRcac[uV
if(sHeader.equals("Content-Length")) z.\\m;s
{ y!:vX6l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zFipuG02
break; TOgH~R=
} 8tf>G(I{
} N+5f.c+S-
else VKu_l
break; <0hVDk~
} ubsv\[:C
} 7bE`P[
catch(IOException e){e.printStackTrace ();} =B'Yx
catch(Exception e){e.printStackTrace ();} i$}G[v<4
)+hJi/g
aO?KRn
Utility.log(nFileLength); B-L@ 0gH
Q>;Aq!mr=
W>Pcj EI
return nFileLength; %}-ogi/c
} wv\"(e7(
qK@,O\
y?3u6q++
//保存下载信息（文件指针位置） OVgak>$
private void write_nPos() EG &me
{ <nV3`L&]
try{ mr_NArF
output = new DataOutputStream(new FileOutputStream(tmpFile)); wt'"<UN
output.writeInt(nStartPos.length); [I'q"yRu]i
for(int i=0;i<nStartPos.length;i++) 1|G5 W:
{ p14$XV
// output.writeLong(nPos); k%-UW%
output.writeLong(fileSplitterFetch.nStartPos); H15!QxD#
output.writeLong(fileSplitterFetch.nEndPos); &`>dY /Y
} ts@e ,
output.close(); XgKYL<k?S
} DIvxut
catch(IOException e){e.printStackTrace ();} s2 aFme
catch(Exception e){e.printStackTrace ();} i?#U>0!
} n[v`F
@Xh8kvc81
,O^kZ}b
//读取保存的下载信息（文件指针位置） B=X_c5
private void read_nPos() l+`CgYo
{ %4#ChlXB
try{ ntL%&wY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q'ib7R;V,
int nCount = input.readInt(); Zw/??Tq b
nStartPos = new long[nCount]; K7(GdKZe
nEndPos = new long[nCount]; eISHV.QV
for(int i=0;i<nStartPos.length;i++) MC B2
{ _jxysFl=
nStartPos = input.readLong(); sv "GX<+
nEndPos = input.readLong(); g&ba]?[A
} ^Ga_wJP8S
input.close(); TC:t!:
} 4zBcq<R7
catch(IOException e){e.printStackTrace ();} ~aL?{kb+
catch(Exception e){e.printStackTrace ();} Hb^ovc0
} mryT%zSlM
abEdZ)$
z!~{3M
private void processErrorCode(int nErrorCode) }y*rO(cu7G
{ `sRys oW
System.err.println("Error Code : " + nErrorCode); Q2@yUDd!
} q^@*k,HG
{w99~?
,? &$c+
//停止文件下载 1ahb:Mjv
public void siteStop() [{ A5BE -
{ IY2f$YV
bStop = true; 5hAs/i9_
for(int i=0;i<nStartPos.length;i++) :ZM=P3QZ
fileSplitterFetch.splitterStop(); @Hp=xC9V
+J}h
wG22ffaki
} oOQ0f |MGp
} ]ddL'>$c$
//负责部分文件的抓取 :?#wWF.
**FileSplitterFetch.java 0J= $ A
*/ BT5~MYBl
package NetFox; *vzj(HGO
k.H4Mf(4
K5+ONA<c
import java.io.*; 5Ak>/QF9
import java.net.*; ]}_Ohe]X
Az(J@
/"1[qT\F
public class FileSplitterFetch extends Thread { zn\$6'"
).$kp2IN
]k.YG!$
String sURL; //File URL p!K]cD
long nStartPos; //File Snippet Start Position g8Zf("
long nEndPos; //File Snippet End Position &=.7-iC|W
int nThreadID; //Thread's ID +j6^g*
boolean bDownOver = false; //Downing is over s! sG)AR.J
boolean bStop = false; //Stop identical k~$}&O
FileAccessI fileAccessI = null; //File Access interface M:K4o%
SR9M:%dga
` B+Pl6l)F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Pj*"2 LBW#
{ .ldBl
this.sURL = sURL; piPV&ytI
this.nStartPos = nStart; Jqt|'G3
this.nEndPos = nEnd; ~$4!C'0
nThreadID = id; v%Su#xq/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T@N)BfkB
} qNbgN{4
:HN\A4=kc(
@'?7au ''
public void run() .[o?qCsw
{ d1d:5b
while(nStartPos < nEndPos && !bStop) ~NO'8Mr
{ 1swqs7rR|
BOW`{=
Vdf~rV
try{ e= _7Q.cn
URL url = new URL(sURL); xa%2w]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J)=Ts({
httpConnection.setRequestProperty("User-Agent","NetFox"); =Xb:.
String sProperty = "bytes="+nStartPos+"-"; RsP^T:M}$
httpConnection.setRequestProperty("RANGE",sProperty); 95 X6V
Utility.log(sProperty); KWT[b?
brt`oR
Cqw`K P
InputStream input = httpConnection.getInputStream(); 0J9Ub
//logResponseHead(httpConnection); YoRD9M~iG~
G/}nwj\
7C^W<SUo
byte[] b = new byte[1024]; '\B!1B>T
int nRead; 'ewVn1ME[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |f"1I4Kg
{ lO^YAOY
nStartPos += fileAccessI.write(b,0,nRead); n0'"/zyc
//if(nThreadID == 1) 0]t7(P"F6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %0Ke4c
} T9Pu V
? `#
Tn\59 (
Utility.log("Thread " + nThreadID + " is over!"); TZS:(MJ9M
bDownOver = true; >U[YSsFt6
//nPos = fileAccessI.write (b,0,nRead); je~gk6}Y
} VxGR[kq$]
catch(Exception e){e.printStackTrace ();} T#R*]
} 4B=@<(H
} VWE`wan<
CZ/:(sOJ
AU H_~SY
//打印回应的头信息 %KmhR2v
public void logResponseHead(HttpURLConnection con) L)/^%/!
{ ,[ M^rv
for(int i=1;;i++) e5.sqft
{ FKu^{'Y6E0
String header=con.getHeaderFieldKey(i); 1FmqNf:V7I
if(header!=null) ST^{?Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o^&nkR
Utility.log(header+" : "+con.getHeaderField(header)); 6ALUd^
else AG<TY<nqL
break; W!WeYV}kb
} '9q:gFO
} |th"ET
's6hCs&|NV
*v9 {f?
public void splitterStop() Eg|C
{ ZuQ\Pyx
bStop = true; :l?/]K
} B"fKv0
/kK:{
@ Yzj
} 91j.%#[v'
t_ZWd#x+;
.2:S0=xt<
/* Z?tw#n[T
**FileAccess.java F6 c1YI[
*//文件访问(定位，写) 8&KqrA86
package NetFox; ]u@`XVEJ
import java.io.*; pj9s=}1 '
,O]AB
AwO'%+Bv
public class FileAccessI implements Serializable{ }=JuC+#~n
05Go*QvV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rA#Ji~
RandomAccessFile oSavedFile; Y!L<& sl
long nPos; G .k\N(l
[I7([l1Wvd
#^&.*'z%z
public FileAccessI() throws IOException 66shr
{ ,2_!hm/
this("",0); @jevY81)
} 5Dlx]_
aXO|%qX
/0I=?+QSo
public FileAccessI(String sName,long nPos) throws IOException ZRo-=/1
{ 2k3yf_N
oSavedFile = new RandomAccessFile(sName,"rw"); meNz0ve
this.nPos = nPos; `di/nv)
oSavedFile.seek(nPos); BY^5z<^.
} 0vm}[a4+i;
i7(\i2_P
QHuh=7u)
public synchronized int write(byte[] b,int nStart,int nLen) E?Ofkc$q
{ j8"2K^h=
int n = -1; 1|zy6
try{ 5uufpvah
oSavedFile.write(b,nStart,nLen); !2Q>
n = nLen; b5Pakz=jNM
} mMRdnf!Uid
catch(IOException e) bkfk9P
{ Rk.GrLp
e.printStackTrace (); vswBK-w(Z
} [v$NxmRu
#[{xEVf
J=qPc}+
return n; bP,_H
} %!e;sL~&
PC}m.tE
SQd`xbIuL
} iNAaTU
z7P]g C$\
=q-HR+
/* Rr>h8Ni <
**SiteInfoBean.java hPHrq{YZ
*/ Du2v,n5@
package NetFox; !HP/`R
vAMr&[
jL[ hB
public class SiteInfoBean { J6Q}a7I#
DfQD!}=
aY7.<p*a
private String sSiteURL; //Site's URL H;OPA8\n
private String sFilePath; //Saved File's Path f:-dw6a=s
private String sFileName; //Saved File's Name Ew kZzVuX
private int nSplitter; //Count of Splited Downloading File t846:Z%[
a:3f>0_t
;c_pa0L
public SiteInfoBean() w+0Ch1$
{//nSplitter的缺省值为5 XiB]I5(hcc
//default value of nSplitter is 5 YQ+Kl[ec
this("","","",5); `b{.K,
} $q6'VLPo
=':,oz^|
}@V,v[&e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) dn1Tu6f;|
{ pH1 9"=p<
sSiteURL= sURL; ohA@Zm8O
sFilePath = sPath; #`0iN+qh
sFileName = sName; 7o4 vf~
this.nSplitter = nSpiltter; K{&b "Ba1
42m}c1R
/j1p^=ARV
} CXsi
h8yv:}XU*
.ZxH#l _
public String getSSiteURL() 6GD Uo}.
{ S0ct;CS
return sSiteURL; Y{8L ~U:
} ^8V cm*
YTco;5/
^<e"OV
public void setSSiteURL(String value) o\luE{H .?
{ (qP !x 2j
sSiteURL = value; 0P_Y6w+
} QJG]z'c+
4D/mm(2d$
>)N}V'9
public String getSFilePath() Lz VvUVk
{ RhJL`>W`
return sFilePath; 2,>q(M6,EA
} Yb|zE
%V$ujun`
N!fp;jvG
public void setSFilePath(String value) TLL.Ch|#Y
{ e< Ee2pGX
sFilePath = value; Z6cG<,DQ
} YSuwV)Y
^j2:fJOU#
IpxFME%!
public String getSFileName() Q#bFW?>y,
{ )W@H
return sFileName; o4kNDXP#S
} 5m+:GiI
/N@0qQ
pg~`NN
public void setSFileName(String value) } V4"-;P
{ Pc]c8~
sFileName = value; Kg@9kJB
} n#N<zC/
;e0>.7m
+{/zP{jH
public int getNSplitter() r,6~?hG]
{ EMH?z2iGd
return nSplitter; `.dTkL
} @T1>%oi
p;n)YY$
U6=m4]~Z
public void setNSplitter(int nCount) )_EobE\
{ Ze$:-7Czl
nSplitter = nCount; Iw"?%k\U
} }}qR~.[
} 8IC((
nm'm*sU\
t:M({|m Y
/* sI`i
**Utility.java #k=!>%+E
*/ ,`|KNw5
package NetFox; !9o8v0ZI
)K2n!Fbd
RpLm'~N'
public class Utility { (oJ#`k:&n
W,agPG\+
j7-#">YL
public Utility() ]-.Q9cjc$q
{ % wRJ"T`Tt
@V:b Co
of& vQ
} nTu"
kd\yHI9A
//线程睡眠 Mdwh-Cis/
public static void sleep(int nSecond) >5 5/@+^
{ Q)a*bPz
try{ *pasI.2s#
Thread.sleep(nSecond); N=+Up\h
} 1*-58N*
catch(Exception e) vJq`l3&
{ T |j^
e.printStackTrace (); OClY,@
} Eun%uah6c
} q>omCk%h
|J}~a8o
//日志 3\@6i'
public static void log(String sMsg) [1vrv(u>
{ NM]6 o
System.err.println(sMsg); I3s}t$`y(
} _ve7Is`/
-`?V8OwY]
d'-^VxO0
public static void log(int sMsg) Dkdm~~Rr
{ <I|ryPU9{X
System.err.println(sMsg); jA]xpf6}
} v5$zz w
} A`r&"i OKA
Y2$%%@
jN {ED_
/* b'{D4/
**TestMethod.java P7Y[?='v
*/ .HtDcGp
package NetFox; 2C8M1^0:Z
$K G?d>wx
zR<jZwo]#
public class TestMethod { :e9E#o
oL6_Ya
3> fuH'=
public TestMethod() ja>Tnfu
{ ///xx/weblogic60b2_win.exe [D?E\Nkk
try{ er<~dqZ}]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (Pu*[STTT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G/`_$ c
SiteFileFetch fileFetch = new SiteFileFetch(bean); XnG!T$
fileFetch.start(); da<1,hF
} H5aUZ=
catch(Exception e){e.printStackTrace ();} D>1Dao
!9N%=6\
L'6zs:i
} >3Y&jsh<
Je*gMq:D
*LhR$(F(
public static void main(String[] args) )i>KYg w
{ 4i19HD_
new TestMethod(); 5y~[2jB:
} UmJg-~
} HU'E}8%t6
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